JPH09218946A - Image rotation circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rotate a rectangular image at the angle of integer multiple of 90 deg. at high speed with small circuit scale by performing write for the unit of row and column through a write selector and performing read for the unit of column or row through a read selector. SOLUTION: This circuit is provided with a matrix cell 1 for writing/reading square data for the unit of (n)×(n) bits, a decoder part 4 for outputting a cell select signal corresponding to the output value of a counter 3, a write selector 5 for inputting a write signal and the cell select signal and outputting the write signal to a valid cell row, and a read selector 6 for inputting a read signal and the cell select signal and outputting the read signal to a valid cell column. The counter 3 is incremented by the write signal or the read signal, and the cell select signal successively changes from '0' to (n-1). Then, by performing a write operation (n) times and performing a read operation (n) times, written image data can be rotated at 90 deg. and outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Regarding an image rotation circuit for rotating 0 ° / 270 °, particularly 90 ° / 270 ° rotation processing of rectangular image data can be performed at high speed using a small-scale circuit,
It relates to an image rotation circuit.

In the image rotation processing method, a rectangular image is rotated by 90 degrees to convert the height and width, or rotated by 270 degrees and inverted to convert the height and width, and displayed on the screen or printed on paper. It is used for the purpose of.

Such an image rotation processing method needs to be able to be executed using a circuit as small as possible and to be capable of high-speed processing.

[0004]

2. Description of the Related Art In a conventional image rotation circuit, an image is rotated by converting the bit sequence of input image data and shifting and storing it in a RAM group.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 63-58583, the original image data is
When rotating 90 degrees to the left, the original image data is input to the conversion circuit, and the arrangement of the bit string of the input data is converted and output according to the 90-degree rotation angle information input to the timing generation circuit. Set in the second data shift circuit. The data set in the first data shift circuit is converted into rotation image data by the n number of m-bit shift registers in the data shift circuit, written in the first RAM via the buffer, and the address is stored in the counter. input. It is described that the rotation image data is written in the second RAM by performing the same operation by the second data shift circuit, the buffer and the second RAM.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 61-49246, the image in the two-dimensional memory is
When the image is rotated by an integral multiple of 0 degrees, the area to be rotated in the image is divided into rectangular areas having a predetermined bit width, and the address information is generated by the address counter. Then, using the address from the counter, the read / write control unit reads the image information from the memory and stores it in the vertical / horizontal conversion buffer, and the address information from the counter is obtained and the corresponding image information is vertically / horizontally converted and latched. Stored in
It is described that the information is stored in a position where a predetermined rotation is made in the memory via a control unit.

[0007]

The conventional rectangular image rotation circuit requires a plurality of shift registers for simultaneously shifting the input data and the output data, and the RAM group for temporarily storing the rotation data. Since it is necessary to have an address generation circuit for generating an address, there is a problem that the circuit scale becomes large.

[0008]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems of the prior art, in which a rectangular image is
An object of the present invention is to provide an image rotation circuit capable of performing image rotation processing for rotating an image at an angle that is an integer multiple of a degree with a small-scale circuit at high speed.

[0009]

[Means for Solving the Problems]

(1) A matrix cell of n rows and n columns that writes and reads image data in bit units, a counter that resets when a write signal and a read signal are generated and counts the number of inputs of the write signal or read signal, and this counter And a decoder unit that outputs a cell selection signal for the matrix cell in accordance with the output value of. In addition, a write selector that sequentially generates n write signals that enable the row or column of the matrix cell in the matrix cell based on the write signal and the cell select signal, and the column of the matrix cell based on the read signal and the cell select signal. Alternatively, a read selector that sequentially generates n read signals that enable the rows in a sequence different from the sequence in which the write signals are generated is provided.

In this (1), more specifically, square data of a matrix cell in which square data can be written / read in n × n bit units and log ₂ n bit countable from 0 to n-1 are used. A counter, a decoder unit that outputs n cell selection signals from 0 to n−1 according to the output value of the counter, and a write signal and a cell selection signal as input A write selector that outputs a write signal and a read selector that inputs a read signal and a cell selection signal and outputs a read signal to a valid cell column are provided.

The counter is initialized to 0 by the reset signal and incremented by the end edge of the write signal or the read signal. As a result, the cell selection signal sequentially changes from 0 to n−1, and a row that becomes valid at the time of writing and a column that becomes valid at the time of reading sequentially move. Then, by performing the write operation n times and the read operation n times, the result obtained by rotating the written image data by 90 degrees can be obtained at the time of reading.

(2) In the case of (1), the read selector
An output order setting unit that reverses the output order of the read signals based on a predetermined external input is also provided. In this case, the write selector is also provided with an input order setting unit that reverses the output order of the write signals based on a predetermined external input.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the basic configuration of an embodiment of the present invention.

In FIG. 1, a memory matrix cell 1
Is composed of n × n 1-bit register groups 2 ₁₁ to 2 _nn , and receives n × n bit data before rotation as input and outputs n × n bit data after rotation. A write signal line and a read signal line are connected to each register cell, a write signal is commonly input in each row, and a read signal is commonly output in each column.

That is, in the memory matrix cell 1,
and n of the write signal c ₁ to c _n, n number of read signals d ₁ to d _n is adapted to be input.

The read / write counter 3 increments by one each time either the write signal e or the read signal f becomes active. The decoder unit 4 is
The output result of the counter 3, that is, the number of times of writing / reading is decoded, and the valid write row or read column information is output to the read selector 5 and the write selector 6.

[0018] The write selector 5, enabled by the write signal, selects whether written into the register cell rows of the memory matrix cell 1 throat by the output of the decoder section 4, at the time of writing, which of the write signal c ₁ to c _n Or output one.

The read selector 6 is enabled by a read signal, selects which register cell column of the memory matrix cell 1 to read from by the output of the decoder section 4, and which _one of the read signals d _{1 to} d _n is read at the time of reading. Or output one.

For example, at the time of the first writing, the output of the counter 3 is reset to 0 by the reset signal g, so the input of the decoder unit 4 is 0. _The write signal c ₁ for ₁₁ to _21n is validated.

Since the counter 3 is incremented by 1 when the first writing is completed, when the second writing is performed, the selector 5 causes the write signal c ₂ for the second register cell row group 2 ₂₁ to _{22 n.} To enable.

In this way, when the writing is completed n times, the output of the counter 3 returns to 0 and the initial state is set.

Next, when reading is performed, the selector 6 operates similarly to the selector 5, and at the time of the first reading,
The read signal d ₁ for the register cell row groups 2 ₁₁ to 2 _{n1 in the} first column is enabled, and the read signal d for the register cell row groups 2 ₁₂ to 2 _{n2 in} the second column is enabled during the second read.
Enable ₂ .

In this way, when the reading of n times is completed, the output of the counter 3 returns to 0 and the initial state is set.

As described above, by performing writing in units of rows and reading in units of columns, it is possible to rotate an image at high speed.

Further, each selector 5, 6 is provided with an output order setting section and an input order setting section for reversing the output order of the read signal and the write signal based on a predetermined external input. Then, the selector 5 or the selector 6 reverses the output order of the write signal or the read signal based on the settings by the output order setting unit and the input order setting unit, thereby rotating by 90 degrees or 270 degrees, respectively. Mirror output of.

The image rotation circuit according to this embodiment is used in a printer device. In the printer device, it is necessary to rotate the character by 90 degrees, or to reverse the character, but this image rotation circuit enables high speed inversion of such rectangular image data.

[0028]

Since the present invention is constructed and functions as described above, according to the present invention, the write selector performs writing in units of rows and columns, and the read selector performs reading in units of columns or rows. The image data thus rotated rotates the rectangular image at a high speed with a small circuit scale as compared with the conventional example. Therefore, in the conventional rectangular image rotation circuit, the output data of the input data is output. It is necessary to have a plurality of shift registers for simultaneously shifting the data and to have an address generation circuit for generating an address of the RAM group for temporarily storing the rotation data. However, the present invention has such a configuration. It is not necessary and therefore the circuit scale becomes large, and the drawback of the conventional example that the operation speed is slow is solved. It is possible to provide an image rotation circuit.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of an embodiment of the present invention.

[Explanation of symbols]

1 memory matrix cell 2 ₁₁ to 2 _nn register cell 3 Write / read counter 4 decoder 5 writes selector 6 read selector a input data b output data c ₁ to c _n write signal d ₁ to d _n read signal e write signal f read Signal g Reset signal

Claims (3)

[Claims] 1. A matrix cell of n rows and n columns that writes and reads image data in bit units, and a counter that resets when a write signal and a read signal are generated and counts the number of inputs of the write signal or the read signal. A decoder unit that outputs a cell selection signal for the matrix cell according to an output value of the counter is provided, and a row or a column of the matrix cell is enabled in the matrix cell based on the write signal and the cell selection signal. And a read selector for sequentially generating n write signals, and a read signal for validating a column or row of the matrix cell based on the read signal and the cell selection signal, in a different order from the write signal generation order. It is equipped with a read selector that sequentially generates n lines. Image rotation circuit according to claim. 2. The image rotation circuit according to claim 1, wherein the read selector is provided with an output order setting unit that reverses the output order of the read signals based on a predetermined external input. 3. The image rotation circuit according to claim 2, wherein the write selector is provided with an input order setting unit that reverses the output order of the write signals based on a predetermined external input.