JP2006253798A - Image processing method and image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing method and an image processor for correcting image defects by properly coping with even the case of when an image as a processing target is not suitable for detection and correction of the image defects. <P>SOLUTION: A defect detection and correction part 40 is composed so that defect detection processing has a plurality of defect detection modes and defect correction processing has a plurality of defect correction modes. The defect detection and correction part executes at least either of operation for selecting a prescribed defect detection mode from among a plurality of the defect detection modes and operation for selecting a prescribed defect correction mode from among a plurality of the defect correction modes on the basis of mode switching conditions after acquiring the mode switching conditions for switching at least either of the defect detection modes and the defect correction modes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing method and an image processing apparatus for detecting an image defect and correcting the detected image defect. More specifically, the present invention relates to an image defect of a photographic film using invisible light such as infrared light. The present invention relates to an image processing method and an image processing apparatus for detecting and correcting the image.

  In recent years, digital photo printers using digital exposure have been put into practical use as devices for printing images taken on photographic films (hereinafter referred to as films) such as negative films and reversal films onto photosensitive materials (printing paper). Yes. A digital photo printer photoelectrically reads an image recorded on a film, converts the read image into a digital signal, and then performs various image processing to obtain image data for recording, which is modulated in accordance with the image data. The photosensitive material is scanned and exposed with recording light to record an image (latent image), and development processing or the like is performed to obtain a (finished) print.

In such a digital photo printer, the exposure condition at the time of printing can be determined by image data processing using the image as digital image data. Therefore, correction of image skipping and blurring caused by backlighting, flash photography, etc., sharpness (Sharpening) Processing, correction of color and density feria, correction of underexposure and overexposure, correction of decrease in peripheral light amount, etc., to obtain high-quality prints that could not be obtained by conventional direct exposure Can do. In addition, a plurality of images can be combined, divided into images, and characters can be combined by image data processing. A print that is freely edited / processed according to the application can be output.
Furthermore, according to the digital photo printer, it is possible to create a print from an image (image data) taken with a digital still camera or the like, and in addition to outputting the image as a print (photo), the image data is also converted to a computer or the like. Can be stored in a recording medium such as a floppy disk, so that the image data can be used for various purposes other than photography.

Such a digital photo printer basically includes a scanner (image reading device) that photoelectrically reads an image recorded on a film, an image processing device that performs image processing on the read image to obtain image data for recording, and The printer is configured by a printer (image recording apparatus) that scans and exposes a photosensitive material in accordance with the image data and develops the photosensitive material for printing.
In a scanner, reading light emitted from a light source is incident on a film to obtain projection light carrying an image photographed on the film, and this projection light is imaged on an image sensor such as a CCD sensor by an imaging lens. Then, the image is read by photoelectric conversion, subjected to various image processing as required, and then sent to the image processing apparatus as film image data (image data signal). Here, in the scanner, the frames are fed by the carrier mounted on the scanner, thereby sequentially reading the images of the frames shot on the film one by one.

  By the way, when reading an image of a film using such a scanner, if foreign matter such as dust or dust adheres to the film or a scratch is formed due to friction or the like, the obtained image data includes: Image defects resulting from scratches due to adhesion of foreign matter or friction are formed. Such image defects are a major factor that causes image quality degradation during printing. Therefore, a method has been proposed in which an image defect is detected from the read image data and the image defect is repaired by image processing.

  As a method for detecting an image defect of a film, for example, a method of reading an image of a film in a non-visible region such as infrared light (IR light) and analyzing the invisible image is known. That is, IR light is not absorbed by the image (pigment) photographed on the film, but is shielded / scattered by image defects, that is, dust and scratches attached to the film. By detecting changes in signal strength, image defects in the film can be detected.

  However, many types of films currently on the market are sensitive to invisible light, and in addition to the visible image, an invisible image is simultaneously formed during exposure recording of the image (so-called image). There is a film. In such a film, the amount of transmitted light of invisible light varies depending on the density of the invisible image, so even if invisible light is used, the amount of transmitted light due to the recorded image is changed and caused by scratches or foreign matter. It is difficult to separate the change in transmitted light amount, and the image defect detection and correction processing may cause a deterioration in image quality such as a dull edge in the image. There was a problem that it took an unnecessarily long time.

  In order to solve such a problem, Patent Document 1 discloses a detection / correction unit that detects a defective portion of an image represented by image information and corrects the detected defective portion with respect to the image information, and a process A determination unit that determines whether the processing target image represented by the target image information is suitable for detection and correction of a defective portion by the detection / correction unit; and a detection unit that detects the defective portion of the processing target image. And detecting or correcting the defective portion by the detection / correction means when it is determined that the detection / correction means is not suitable, or suitable for detection and correction of the defective portion by the determination means in the processing target image. An image processing apparatus is disclosed that includes a control unit that performs control so that a defective portion is detected and corrected only in a region excluding a region that is determined not to exist.

JP 2002-281303 A

In the image processing device disclosed in Patent Document 1, it is determined whether or not the image to be processed is suitable for detection and correction of a defective portion (image defect), and is determined not to be suitable for detection and correction of a defective portion. In this case, since the detection and correction of the defective portion is performed only for the region excluding the region determined to be not suitable for detection and correction of the defective portion or the detection and correction of the defective portion is prohibited. It is possible to prevent the image quality from being deteriorated due to the processing or taking more time than necessary.
However, in the image processing apparatus described in Patent Document 1, since it is determined whether or not the processing target image is suitable for detection and correction of the defective portion, the processing target image is used for detection and correction of the defective portion. If it is not suitable and it is determined that the detection means does not perform detection and correction, the defective portion could not be corrected.

  The present invention has been made in consideration of such circumstances, and the object of the present invention is to appropriately cope with even when the image to be processed is not suitable for detection and correction of image defects. An object of the present invention is to provide an image processing method and an image processing apparatus capable of correcting an image defect.

  In order to solve the above-described problem, the first aspect of the present invention is a defect detection process for detecting an image defect of the document from image data obtained by photoelectrically reading the document on which the image is formed, and the defect A defect correction process for correcting the image defect obtained by the detection process, wherein the defect detection process has a plurality of defect detection modes, and the defect correction process has a plurality of defect correction modes. Obtaining a mode switching condition for switching at least one of the defect detection mode and the defect correction mode, and selecting a predetermined defect detection mode from the plurality of defect detection modes based on the mode switching condition And an image processing method for performing at least one of selecting a predetermined defect correction mode from the plurality of defect correction modes.

  In the image processing method of the present invention, the mode switching condition is preferably at least one selected from the group consisting of film imaging conditions, image properties, image defect properties, image defect positions, and film sensitivity. .

  The defect correction mode preferably includes a mode in which correction accuracy is important and a mode in which correction speed is important. The defect detection mode may include a mode in which detection accuracy is important and a mode in which detection speed is important. preferable.

  In the present invention, it is preferable that the original is a photographic film, and the image defect is a scratch formed on the photographic film or a foreign matter attached to the photographic film.

  According to a second aspect of the present invention, a defect correction process for detecting an image defect of the document from image data obtained by photoelectrically reading the document on which an image is formed, and correcting the image defect obtained thereby. The defect correction processing unit has a plurality of defect detection modes and a plurality of defect correction modes, and is for switching at least one of the defect detection mode and the defect correction mode. Acquiring a mode switching condition and selecting a predetermined defect detection mode from the plurality of defect detection modes based on the mode switching condition; and selecting a predetermined defect correction mode from the plurality of defect correction modes. An image processing apparatus that performs at least one of the above is provided.

  In the image processing apparatus of the present invention, the mode switching condition is preferably at least one selected from the group consisting of film imaging conditions, image properties, image defect properties, image defect positions, and film sensitivity. .

  The defect correction mode preferably includes a mode in which correction accuracy is important and a mode in which correction speed is important. The defect detection mode may include a mode in which detection accuracy is important and a mode in which detection speed is important. preferable.

  Preferably, the original is a photographic film, and the image defect is a scratch formed on the photographic film or a foreign matter attached to the photographic film.

  According to the image processing method and the image processing apparatus of the present invention, even when the image to be processed is not suitable for detection and correction of image defects, for example, even in a place where the image changes drastically like a person. In the defect detection process, an image defect is detected by selecting an optimum detection mode based on the mode switching condition, so that an image defect can be detected appropriately. Also in the defect correction process, the mode switching condition is set. Based on this, the image defect is corrected in the optimum image correction mode, so that the detected image defect can be corrected appropriately.

  Hereinafter, an image processing apparatus of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 shows a block diagram of an example of a digital print system using the image processing apparatus of the present invention.
The digital print system 10 shown in FIG. 1 photoelectrically reads an image photographed on a film F and outputs it as a print. Basically, the scanner 12, the image processing device 14 of the present invention, and an output Device 16.

First, the scanner 12 will be described.
The scanner 12 is a device that photoelectrically reads an image photographed on the film F. As schematically shown in FIG. 1, the white light source 22, the variable aperture 24, the color filter plate 26, the diffusion box 28, the carrier 30, It has an imaging lens unit 32, an area CCD sensor 34, and an A / D (analog / digital) converter 36.

The light source 24 can be configured using, for example, a halogen lamp, and can irradiate the film F with light. The light emitted from the light source 24 enters the diffusion box 28. The diffusion box 28 can make the light incident on the film F uniform in the film surface direction.
The variable aperture 24 is used to adjust the amount of light irradiated on the film. The color filter plate 26 is a turret having R (red), G (green), B (blue), and IR (infrared) color filters. The color filter plate 26 is rotated by a known rotating means. Thereby, each color filter can be inserted into the optical path of the reading light.

The carrier 30 can convey the film F intermittently, and can sequentially convey and hold each image (each frame) photographed on the film F to a predetermined reading position. The carrier 30 is prepared in a plurality of types according to a new photo system (Advanced Photo System), a film size such as 135 size, and the like, and is configured to be attachable to the main body of the scanner 12. By exchanging the carrier 30, various types of films and processing can be handled. Images (frames) photographed on a film and used for print creation are transported to a predetermined reading position by the carrier 30 and held.
The carrier 30 has a reader (not shown) that reads a DX code or the like recorded on the film F. A carrier corresponding to the new photographic system has a magnetic head for reading information recorded on the magnetic recording medium of the film F. The information read by these is sent to the image processing device 14.

  The imaging lens unit 32 can image the projection light of the film F at a predetermined position of the area CCD sensor 34. The area CCD sensor 34 is a device for photoelectrically reading the film F, and reads the entire surface of one frame regulated by the mask of the carrier 30 (image reading by surface exposure).

  In such a scanner 12, when reading the film F, first, the film F is conveyed by the carrier 30, and a frame to be read (usually the first frame or the last frame) is conveyed to the reading position.

  The reading light emitted from the light source 22 is adjusted in light amount after being adjusted by the variable diaphragm 24 and then incident on the R color filter of the color filter plate 26, for example. Then, after the amount of light is made uniform in the surface direction of the film F by the diffusion box 28, the light is incident on and transmitted through the film F held at a predetermined reading position by the carrier. The carrying projection light is obtained. This projection light is imaged by the imaging lens unit 32 at a predetermined position of the area CCD sensor 34 (light receiving surface of the area CCD sensor), and the R image of this frame is read photoelectrically.

By rotating the color filter plate 26 and sequentially passing the reading light through the G and B color filters, the G and B images of this frame are read, and finally the IR color filter is transmitted. , Reading by IR is performed, and reading of this frame is finished. Therefore, the scanner 12 outputs four-channel image signals of R, G, and B visible images and IR (invisible image).
When the reading of one frame is completed, the film F is conveyed, and the next frame to be read is conveyed to the reading position.

  An output signal from the area CCD sensor 34 is amplified by an amplifier (not shown), converted to a digital image signal by an A / D converter 36, and output to the image processing device 14.

In the printing system 10, in order to determine a main scan for reading an image at a high resolution for printing or the like for each frame, and a reading condition of the main scan and an image processing condition in the data processing unit 14. The image reading is performed twice, that is, the pre-scan that is an image reading at a low resolution performed prior to the main scan.
In this case, normally, the output signals of the pre-scan and the main scan are basically the same data except that the resolution and the output level are different.

  In the digital print system of the present embodiment, the scanner (image reading means) 12 is not limited to the one using such an area sensor, and reads an IR image in addition to R, G and B 4 It may be a scanner that reads an image by so-called slit scanning using a line CCD sensor. The light source 22 may use an LED (Light Emitting Diode), for example, three types of LEDs that emit visible light of R (red) light, G (green) light, and B (blue) light, and The light source may be configured by arranging LEDs that emit IR (infrared) light which is invisible light. In this case, the color filter plate 26 is not necessary, and each LED light source is driven to emit visible light and IR light sequentially and read by the area CCD sensor, and the visible image of R, G, B and IR. Invisible images can be obtained.

Next, the image processing device 14 will be described. As described above, the digital image signal output from the scanner 12 is input to the image processing device 14.
As shown in FIG. 1, the image processing apparatus 14 includes an image data processing unit 38 and a defect detection / correction unit 40. A display 20 and an input device 18 are connected to the image processing device 14. The input device 18 includes a keyboard 18a and a mouse 18b.
Here, the image data processing unit 38 will be described. FIG. 2 shows a block diagram of the image data processing unit 38.
As shown in FIG. 2, the image data processing unit 38 includes a data correction unit 44, a log converter 46, a frame memory 48 (hereinafter referred to as FM 48), an enlargement / reduction unit 50, an image correction unit 52, a color correction unit 54, a floor. A tone conversion unit 56, a data conversion unit 58, and a storage unit 60 are included.

  The image data processing unit 38 of the digital print system 10 branches downstream from the Log converter 46 (data flow direction) in order to process prescan data and display a simulation image for verification. A processing path basically similar to the processing path from the FM 48 to the data conversion unit 58 may be provided.

  The data correction unit 44 applies predetermined corrections such as DC offset correction, dark correction, and shading correction to the R, G, B, and IR output data output from the scanner 12. The Log converter 46 performs Log conversion on the output data processed by the data correction unit 44 by using, for example, an LUT (Look Up Table) or the like to obtain digital image (density) data. The R, G, B, and IR image data converted by the Log converter 46 are stored in the corresponding FM 48, respectively.

  The image data stored in the FM 48 is then subjected to enlargement / reduction processing (electronic scaling processing) on the image data having a size (number of pixels) corresponding to the output by the enlargement / reduction unit 50. Of the image data processed by the enlargement / reduction unit 50, the IR image data is output to the storage unit 60 as it is and stored at a position corresponding to this frame.

On the other hand, the image data of the R, G, and B visible images processed by the enlargement / reduction unit 50 is subjected to predetermined image correction such as sharpness processing by the image correction unit 52 and then the color correction unit 54. Color correction (saturation correction) is performed using a matrix or the like.
The image data of the visible image processed by the color correction unit 54 is then subjected to gradation conversion including density correction and color balance adjustment by a one-dimensional lookup table (LUT) in the gradation conversion unit 56. Is done. When the film F is a negative film, the tone conversion converts the negative image (density) data into positive image (density) data corresponding to the output.

The data converter 58 converts the tone-converted image data into image data corresponding to print output using a three-dimensional (3D) -LUT or the like. Each image data of the converted R, G, and B visible images is sent to the storage unit 60 and stored at a position corresponding to this frame, similarly to the IR image data.
That is, in the illustrated example, image data of three visible images of R, G, and B and image data of IR (non-visible image) in total for four frames are stored in the storage unit 60 for one frame. Remembered. The storage unit 60 may be configured using a fixed recording device such as a hard disk, or may be configured using various removable recording media (removable storage) such as a CD-R or MD.

  In the digital print system 10, the image data processed by the data converter 58 may be converted into an image file (digitized) and output to a recording medium such as a CD-R. Both the print and the image file are output. May be.

Next, the defect detection / correction unit 40 will be described.
The defect detection / correction unit 40 detects image defects such as white spots or streaky irregularities caused by foreign matters such as dust and dirt attached to the film F, scratches on the film F such as damage caused by friction, The image defect can be automatically corrected by interpolation of image data or the like.

  In an image processing apparatus for correcting a normal image defect, an image defect is detected using IR image data, and all image defects are automatically corrected by interpolation of the image data. However, in automatic correction using interpolation or the like, it is possible to perform appropriate correction for the size of an image defect or a pattern where an image defect exists, for example, a place where the image changes drastically like a human eye. As described above, there are many cases where an image is unnatural and unnatural and has a problem in image quality. As described above, when the correction is inappropriate, it is determined that the automatic correction is not performed and the defect correction is not performed, so that the defect may remain as it is.

  On the other hand, in the defect detection / correction unit 40 of the digital printing system 10 using the present invention, modes such as film imaging conditions, image defect properties, image properties in areas where image defects exist, image defect positions, etc. Based on the switching condition, an optimum defect detection mode or image correction mode is selected to detect or correct the image defect. As a result, it is possible to output a high-quality image corrected appropriately. That is, even in a place where the image changes drastically like a human eye, it is possible to detect an image defect in a detection mode suitable for it and to correct the detected image defect in an appropriate correction mode. it can.

  In the present embodiment, the defect detection / correction unit 40 has a plurality of types of defect detection modes and a plurality of types of defect correction modes. The defect detection / correction unit 40 automatically or manually selects an optimum defect detection mode and defect correction mode from a plurality of types of defect detection modes and a plurality of types of defect correction modes based on a mode switching condition described later. Image defect detection processing and correction processing can be performed. Examples of the defect detection mode include a detection mode in which accuracy is more important than processing speed, and a mode in which speed is more important than processing accuracy. The defect correction mode can include a correction mode in which accuracy is more important than processing speed, a mode in which speed is more important than processing accuracy, and the like. The defect correction mode can be changed according to the used defect detection mode.

  Hereinafter, the operation of the defect detection and correction unit 40 will be described to describe the image processing apparatus 14 of the present invention in more detail.

  When detecting and correcting an image defect, the defect detection and correction unit 40 reads out image data of four channels (R, G, B, and IR) of frames for correcting an image defect from the storage unit 60 of the data processing unit 14. Is read. Then, a mode switching condition is acquired, an appropriate defect detection mode is selected from a plurality of defect detection modes based on the mode switching condition, and an image defect is detected using IR image data. Further, an image defect is corrected by selecting an appropriate defect correction mode from a plurality of defect correction modes based on the mode switching condition. In the present invention, a detection process similar to the conventional one may be used for the process of detecting an image defect, and an optimum mode may be selected from a plurality of defect correction modes for correcting the detected image defect. .

Here, the principle of defect detection will be described.
When the film F has foreign matters or scratches, the visible light of R, G, and B, and the invisible light such as IR are absorbed, shielded, and scattered by these. Accordingly, when foreign matter or the like is present on the film F, the light intensity of the projection light of the film F that is incident on these positions and incident on the reading unit 34 (CCD sensor) is low.
On the other hand, for the image (visible image) photographed on the film F, the visible light of R, G and B is absorbed according to the image and the light intensity of the projection light changes, but the IR light is the image. Is not absorbed at all and passes through the film F. Therefore, if there is no foreign matter on the film F, basically, the IR light has the same intensity on the entire surface of one frame (area CCD sensor), and the IR image data is uniform for all the pixels of one frame. That is, when the film F has foreign matter or scratches, the intensity of IR light transmitted through the film F, that is, IR image data varies accordingly.

  The defect detection / correction unit 40 uses this to detect the image defect of this frame using the IR image data. Further, in the present invention, the defect detection / correction unit 40 acquires the mode switching condition, and selects a desired condition based on the acquired mode switching condition from the plurality of types of defect detection mode and the plurality of types of defect correction mode. A defect detection mode and a defect correction mode are selected to detect and correct an image defect.

Examples of the mode switching condition used for switching between the defect detection mode and the defect correction mode include film imaging conditions, image properties, image defect properties, image defect positions, film sensitivity, and the like.
Film imaging conditions include 135, film size such as Broni, IR noise amount in IR image data, and the like. The film size can be obtained from, for example, a reader provided on a carrier that reads a DX code or the like or a magnetic head that reads information recorded on a magnetic recording medium of a film. Further, the IR noise amount can be acquired by using a known method such as a method of calculating the dispersion of IR image data.

  The image property means whether it is a flat portion such as the sky, a texture, or a main subject. When the image property is used as the mode switching condition, R, G, and B image data may be used to determine the image property. For example, in the case of the main subject as the property of the image, the main subject extraction process may be executed using the R, G, and B image data. Alternatively, the image may be displayed on a display, and the operator may specify the property of the image via the input device.

  In addition, the nature of image defects refers to the type of scratches such as scratches or scratches, adhered foreign matter, scratch level, scratch depth, scratch thickness, scratch length, or foreign particle size. means. The level of scratches in the case of scratches can be determined by, for example, the connectivity of scratch pixels. In addition, the level of scratches in the case of a scratch can be determined by, for example, the scratch density within a certain area.

  The defect detection / correction unit 40 can acquire and determine the mode switching condition described above, and can switch at least one of the defect detection mode and the defect correction mode to the optimum mode. For example, when the film size is used as the mode switching condition, the defect detection mode and the defect correction mode are switched to the speed-oriented mode when the film size is 135, and the accuracy-oriented mode is selected when the system is Broni. Switch. By automatically switching at least one of the defect detection mode and the defect correction mode according to the film size to be imaged in this way, it is possible to automatically perform optimum image processing without requiring any user operation.

  Further, when the film is scanned with IR light, if the IR light irradiation time is shortened with an emphasis on high speed, noise components may increase due to insufficient IR light storage time. In such a case, the amount of IR noise is detected, and when the amount of IR noise is large, the defect detection mode and / or the defect correction mode based on the assumption that the amount of noise is large are selected to detect image defects. A modification can be made.

Further, when the property of a defect is used as the mode switching condition, first, a defect detection process is executed to detect the defect, and it is determined whether the detected defect is a flaw or a foreign object. If it is a scratch, it is determined whether it is a scratch or a scratch, and the thickness, length, depth, level, etc. of the scratch are determined. Then, based on the determination result, a defect correction mode optimum for correcting the defect is selected.
As described above, the level of the scratch can be determined by, for example, the connectivity of the scratch pixels. Further, the level of the scratch can be determined by, for example, the scratch density within a certain area. An existing method can be used to determine the level of such scratches or scratches. In the case of a scratch, since it can be corrected by simple interpolation from around the scratch, a defect correction mode to be corrected by simple interpolation may be selected. On the other hand, in the case of a scratch, there are few normal images around the detected scratch, and the image may become unnatural by correction by interpolation. In such a case, a defect correction mode that weakens the correction level may be selected, or the mode may be switched to a mode in which no flaw correction is performed or a mode in which correction is performed manually. Here, weakening the correction level means that the corrected pixel value is calculated by weighting the pixel value calculated by the interpolation and the pixel value of the original image instead of correcting the pixel only by interpolation.

  Further, when the image property is used as the mode switching condition, at least one of the defect detection mode and the defect correction mode is switched to the optimum mode according to the image property. The nature of the image can be determined based on, for example, R, G, and B image data. For example, when a flat area such as the sky exists in the image, a defect detection mode and / or a defect correction mode in which processing speed is emphasized is selected for the flat area. In addition, when there is a texture area in an image, defect correction by interpolation is often difficult, so a manual defect detection mode and defect correction mode are selected for the texture area. In addition, when a main subject exists in the image, the quality requirement for the main subject is high, and therefore a defect detection mode and a defect correction mode in which accuracy is emphasized are selected for the area where the main subject exists.

  Here, the method of switching between at least one of the defect detection mode and the defect correction mode according to the property of the image has been described. However, the present invention is not limited to this, and an image defect is detected and an image of an area in which the detected image defect exists is detected. Only the defect correction mode may be switched according to the property. In this case, the nature of the image is determined for the region where the image defect is detected, and the defect correction mode is switched to the optimum mode based on the determination result. For example, if the area where the defect is detected by the defect detection process is flat, such as empty, it is not always necessary to perform high-precision correction. Make corrections. In addition, when a defect is detected by the defect detection process, the area is textured, and the detected scratch is thick, the quality is deteriorated by interpolation and the image becomes unnatural. There is. In this case, the scratch is not corrected or the mode is switched to the manual defect correction mode. Alternatively, a warning may be issued to the operator to inquire whether or not to manually correct the scratch. If defects detected by the defect detection process exist in the image area of the main subject, the quality of the main subject, especially the face, etc. is severe. To correct.

  In addition, when using the position of the image as the mode switching condition, when detecting and correcting the image defect, the image is divided into a plurality of areas, and a different defect detection mode or defect correction mode is selected for each area. Defect detection and correction may be performed. For example, since the influence of shading of IR light is different between the central portion and the peripheral portion of the image, defect detection and correction can be performed using a defect detection mode and a defect correction mode in consideration of the influence. Specifically, the shading level for each area is stored for each imaging condition, and the defect detection or correction is performed after performing processing for canceling the offset of IR light due to shading. Alternatively, the defect detection and correction may be performed after the shading level is estimated by applying a low-pass filter to the IR image.

In addition, since there is a high possibility that the main subject is reflected in the center of the image, the defect detection mode and defect correction mode that emphasizes accuracy are selected in the center to detect and correct defects in the image, In the peripheral portion, detection of image defects may be executed in a defect detection mode or a defect correction mode that emphasizes speed.
Further, the position of the defect can be used as the mode switching condition. In this case, the defect correction mode may be switched to the optimum mode for each region where the defect exists.

  In the present invention, the defect detection mode and the defect correction mode may be switched automatically or may be set by an operator. For example, in a highly important part such as a face, or a part that is difficult to correct such as a texture, a warning is displayed on the display to notify the operator whether or not to execute correction processing in the manual mode. May be. The operator can perform an image defect correction process in the manual mode as necessary. In the case of correcting the defect in the manual mode, for example, the following may be performed. First, R, G, and B image data are displayed on the display 20 as visible images, and a defect detection result is also displayed on the display 20. Defects may be displayed, for example, by a method such as indicating the detected defect in a color such as red, which is easy to distinguish, or indicating with an arrow. Further, when displaying defects in color, an image based on R, G, and B image data may be displayed in black and white so as to facilitate discrimination.

In addition, a processing tool (for example, a manual correction instruction button, a retouch tool, and an automatic correction start button) using a GUI (Graphical User Interface) is displayed on the display 20.
The image displayed on the display 20 may display the entire frame, or may be a partial display so that the entire screen can be confirmed by vertical and horizontal scrolling, screen switching, or the like.

When the image is displayed, the operator uses the input device 18 (keyboard 18a or mouse 18b) to select and input an image defect that is determined to be difficult to correct appropriately by automatic correction such as interpolation.
Selection or input may be performed by a known method using a GUI such as designation of an area including an image defect or designation (click) of the image defect itself. Further, the image defect instructed to be manually corrected may be easily discriminated by changing the color, displaying a surrounding frame, or the like.

When all the image defects to be manually corrected are designated, the operator presses an automatic correction start button. As a result, in the R, G, and B visible image data, automatic correction of image defects is started except for image defects that are not instructed to be manually corrected.
In this example, an image defect to be manually corrected is selected and the others are automatically corrected. However, the present invention is not limited to this, and conversely, even if an image defect to be automatically corrected is selected. Alternatively, both image defects to be manually corrected and image defects to be automatically corrected may be selected. Further, when there is an erroneous detection of an image defect, an instruction not to correct the part may be input.

  The method for automatically correcting image defects is not particularly limited. A method for correcting (filling in) pixels of an image defect by using the continuity of peripheral pixels, interpolation using image data of peripheral pixels, and the like. A known method such as an adjustment method or a method of blurring an image defect portion by applying a low-pass filter or the like can be used.

When the automatic correction of the image defect is completed or in parallel with the automatic correction, the operator corrects the image defect selected as the manual correction in the R, G, and B visible image data.
This image correction may be performed in the same manner as the image correction using a commercially available retouch software such as Adobe's photo shop on a personal computer or the like using a retouch tool, or the image processing device 14 ( Image correction may be performed using commercially available retouching software in the printing system 10).

  Thus, in the present invention, image defects that can be automatically corrected by interpolation or the like are automatically corrected, and image defects that are difficult to be automatically corrected can be manually corrected by an operator. As a result, while ensuring good workability, it is possible to appropriately correct all image defects and output a high-quality image without an unnatural pattern.

The image processing apparatus 14 has been described above. Next, the output device 16 will be described.
The output device 16 is a digital color printer, and includes an image memory 62, R, G, and G laser light sources 64, a laser driver 66, a polygon mirror 68, and an fθ lens 70. The output device 16 reads the image data for recording output from the image processing device 14 and stored from the image memory 62, and modulates the laser beam by the laser driver 66 based on the image data. The laser beam is scanned on the photographic paper P through the rotating polygon mirror 68 and the fθ lens 70, and an image is recorded on the photographic paper P. The photographic paper P on which an image has been recorded is sent to a processor, where color development, bleach-fixing, washing with water, and drying are performed. As a result, the image recorded on the photographic paper is visualized.

  In the illustrated print system 10, the image data processed by the image processing device 14 may not be output as a print, but the image data may be converted into an image file and output to a recording medium such as a CD-R.

As an example, when outputting an image file in JPEG (Joint Photographic Expert Group) format, first, the image data corrected by the image processing device 14 is converted by a 3D-LUT or the like to support output of the image file. Image data, for example, s-RGB standard image data. Next, the image data is processed by the quantization table and the Huffman table to be JPEG compressed to form a baseline image file in the JPEG format.
Furthermore, if necessary, an Exif (Exchangeable Image File Format) format tag is attached to the image file to form a so-called JPEG (Exif) format image file, and a thumbnail image is added if necessary. The image file is output to a recording medium such as a CD-R. Further, whether or not image defects are corrected may be added to the image file as a tag.

  When outputting an image file, the recording medium is not particularly limited, and various known recording media such as MO, smart media, Hi-FD, Zip, and hard disk can be used in addition to the CD-R. It is. In addition to the recording medium, the image file may be output to a communication network such as the Internet or a personal computer connected to the print system 10 via an interface.

  Although the image processing method and the image processing apparatus of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Of course it is good.

For example, in the image processing apparatus 14 of the illustrated printing system 10, the image data processing unit 38 and the defect detection / correction unit 40 are configured separately, but the present invention is not limited to this, for example, The defect detection / correction unit 40 may be configured as one integrated device such as the image data processing unit 38 incorporated therein.
At this time, detection and correction of the image defect may be performed at any position in the path from the scanner 12 to the printer 16, but is preferably performed downstream of the enlargement / reduction unit 50. When there is a possibility that the image defect is emphasized by the sharpness processing, it is preferable to correct the image defect upstream from the image correction unit 52. Further, at this time, image data that has undergone predetermined processing including image defect correction may be output to the printer 16 (recording medium) without arranging a storage unit downstream of the 3D-LUT.

  Moreover, although the said embodiment demonstrated the structure which reads an image by photoelectrically converting the light which permeate | transmitted the photographic film, it is not limited to this, By photoelectrically converting the light which reflected the photographic film, A configuration for reading an image may be employed. The original to be read is not limited to a photographic film, and a photographic material, plain paper, an OHP sheet, or the like may be used as an original for reading.

1 is a block diagram illustrating an outline of an embodiment of a digital print system that performs an image processing method of the present invention and includes an image processing apparatus of the present invention. It is a block diagram which comprises the image data processing part of the image processing apparatus of the digital print system shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Digital photo printer 12 Scanner 14 Image processing device 16 Output device 18 Input device 20 Display 22 Light source 24 Variable aperture 26 Color filter board 28 Diffusion box 30 Carrier 32 Coupled lens unit 34 Area CCD sensor 36 A / D converter 38 Image data processing Unit 40 defect detection correction unit 44 data correction unit 46 log converter 48 frame memory (FM)
50 Enlargement / Reduction Unit 52 Image Correction Unit 54 Color Correction Unit 56 Gradation Conversion Unit 58 Data Conversion Unit 60 Storage Unit 62 Image Memory 64 Laser Light Source 66 Laser Driver 68 Polygon Mirror 70 fθ Lens

Claims (10)

A defect detection process for detecting an image defect of the original document from image data obtained by photoelectrically reading an original on which an image is formed; and a defect correction process for correcting the image defect obtained by the defect detection process. An image processing method comprising:
The defect detection process has a plurality of defect detection modes, and the defect correction process has a plurality of defect correction modes,
Obtaining a mode switching condition for switching at least one of the defect detection mode and the defect correction mode;
Image processing for performing at least one of selecting a predetermined defect detection mode from the plurality of defect detection modes and selecting a predetermined defect correction mode from the plurality of defect correction modes based on the mode switching condition Method.   2. The image according to claim 1, wherein the mode switching condition is at least one selected from the group consisting of film imaging conditions, image properties, image defect properties, image defect positions, and film sensitivity. Processing method.   The image processing method according to claim 1, wherein the defect correction mode includes a mode in which correction accuracy is important and a mode in which correction speed is important.   The image processing method according to claim 1, wherein the defect detection mode includes a mode in which detection accuracy is important and a mode in which detection speed is important.   The image processing according to any one of claims 1 to 4, wherein the original is a photographic film, and the image defect is a scratch formed on the photographic film or a foreign matter attached to the photographic film. Method. An image processing apparatus having a defect correction processing unit that detects an image defect of the document from image data obtained by photoelectrically reading a document on which an image is formed, and corrects the image defect obtained thereby. ,
The defect correction processing unit has a plurality of defect detection modes and a plurality of defect correction modes, acquires a mode switching condition for switching at least one of the defect detection mode and the defect correction mode, and switches the mode. An image processing apparatus that performs at least one of selecting a predetermined defect detection mode from the plurality of defect detection modes and selecting a predetermined defect correction mode from the plurality of defect correction modes based on a condition.   7. The image according to claim 6, wherein the mode switching condition is at least one selected from the group consisting of film imaging conditions, image properties, image defect properties, image defect positions, and film sensitivity. Processing equipment.   The image processing apparatus according to claim 6, wherein the defect correction mode includes a mode in which correction accuracy is important and a mode in which correction speed is important.   The image processing apparatus according to claim 6, wherein the defect detection mode includes a mode in which detection accuracy is important and a mode in which detection speed is important.   The image processing according to any one of claims 6 to 9, wherein the original is a photographic film, and the image defect is a flaw formed on the photographic film or a foreign matter attached to the photographic film. apparatus.

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