JPS5941084A - Random reading method of picture memory - Google Patents

Abstract

PURPOSE:To generate the address of a picture memory rapidly with a simple circuit, by shifting the reading start address of the contents of a Y random number memory by one address in each completion of reading-out of random number data in an X random number memory. CONSTITUTION:When the 1st random number data are read out, a random number memory address counter 4 is counted up by ''1'' by a ready signal from a control part and the 2nd random data from the X random number memory 2 and the Y random number memory 3 are outputted as addresses AX2, AY2. When the random number data up to the n-th data from the memories 2, 3 are successively outputted as addresses AXn, AYn, a borrow signal is outputted from an n-down counter 6 and a reading start address shifting counter 5 for the memory 3 is counted up by ''1'', so that the address specification of the memories 2, 3 for the succeeding n-times is shifted by one by an adder 7. By repeating said operation until the counted value of the counter 5 reaches n, the address of the picture memory can be rapidly specified without repeating all the addresses of the nXn matrix of the picture memory 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an image memory random reading device used for randomly displaying or analyzing each picture element of an image.

Video signals (image signals), z, y from a scintillation camera, etc. are stored on an image memory, and after a certain period of time, the video signals x, y accumulated on the image memory are output to a display device such as an oscilloscope. When displaying simply using the raster scan method, moiré fringes occur at points where the display speed and power frequency are synchronized.

In order to remove these moiré fringes, a method is used in which addresses AxrAy of a two-dimensional matrix-shaped image memory are randomly generated.

This method of randomly generating the addresses Ax and Ay of the image memory involves accessing one pixel, generating a trap random number, storing the address in the memory for the processing unit (hereinafter referred to as CPU), and then After checking that the data is not being used, the data is sent to a display device or an analysis device.

Such conventional devices have the following drawbacks.

(1) The circuit for random number generation and its software become complicated.

(2) It takes too much time to generate random numbers.

(3) Since repeated access is not performed, a determination memory of the same size as the image memory is required.

(4) It takes too much time to determine whether to make repeated accesses.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image memory random readout device that eliminates the drawbacks of the conventional devices and randomly generates addresses of a two-dimensional matrix or box-shaped image memory at high speed with a simple circuit. It is in.

The present invention has been made to achieve the above object, and is characterized by a predetermined non-repetitive
An X random number memory for storing random number data in the direction, a Y random number memory for storing predetermined non-repetitive random number data in the Y direction, and means for sequentially reading the random number data stored in the image memory; and means for shifting the start address for reading the contents of the Y random number memory by one address each time the reading of the random number data from the X random number memory is completed, and randomizing the read address of the contents of the image memory. There are times when I tried to make it occur.

Hereinafter, the present invention will be described in detail along with examples.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, 1 is a two-dimensional Luxluma matrix, a box-shaped image memory, and 2 is a predetermined 1-% without repetition.
-X random number memory for storing random number data in the X direction up to n, 3 is a predetermined non-repeating 1 to n
4 is a random number memory address counter that generates the addresses of X and X random number memories 2 and 3; 5 is a shift counter for the start address for reading the contents of the Y random number memory; 6 7 is a pull-down counter that generates a signal for controlling the counter 5, that is, a borrow signal, and 7 is an adder.

Next, the operation of this embodiment will be explained with reference to FIG.

Predetermined non-repetitive random number data in the X direction from 1 to 71 is generated and stored in an X random number memory 2. Similarly, repeating random numbers from 1 to n, which are different from the contents of the X random number memory 2, are stored in the X random number memory 6.

Then, when the apparatus is started, the first random number data of the X random number memory 2 and the X random number memory 6 are read out and output as addresses Axl and Ayl, respectively, and the addresses corresponding to the addresses AXI and Ayl of the image memory are The image data is accessed and read out.

When this first random number data is read, the control unit (
The random number memory address counter 4 is incremented by "+1" in response to a ready signal from (not shown).
The second random number data of the X random number memory 2 and the X random number memory 6 is output as address Ax2 + Ay2. In this way, the random number data up to the nth in the X random number memory 2 and the X random number memory 3 are sequentially stored at the address Axn+A.
When it is output as yn, a low signal is output from the down counter Δ, the content reading start address shift counter 5 of the X random number memory 6 is incremented by 11, and the adder 7 outputs the next X random number memory 2 and X random number. The address instructions of the memory 3 will be shifted by one.For example, when the X random number memory 2 is outputting the m-th random number data, the X random number memory 6 will output the m-4-1th random number data. In this way, by repeating this until the count number of the shift counter 5 reaches 1, the number of times the image memory 1 of the image memory 1 of
It is possible to specify all addresses randomly and quickly without repeating them.

In this embodiment, an image taken by a scintillation camera or the like has been described, but it goes without saying that the present invention can be applied to processing image display, two-image analysis, etc. using an image memory. In addition, within the scope of not changing the gist of the present invention,
It goes without saying that it can be changed in various ways.

As explained above, according to the present invention, the following effects can be obtained.

(1) The circuit for generating random numbers for creating addresses and its software become simpler.

(2) The time required to generate random numbers can be shortened.

(3) There is no need for a memory for judgment and its judgment time to prevent repeated accesses.

Effects (1) to (3) allow for instructions to be given randomly and at high speed without repeating the addresses of the two-dimensional matrix or box-like image memory.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention. 1-n X n matrix, box-shaped image memory 2 Collection joy

Claims (1)

[Claims] An image memory for recording image data, an X random number memory for storing predetermined non-repetitive random number data in the X direction, and a predetermined non-repetitive Y random number memory. an X random number memory for recording random number data in the direction; means for sequentially reading the random number data stored in the X, X random number memory; and each time reading of the random number data from the X random number memory is completed; An image memory random reading device characterized in that it comprises means for shifting the content reading start address of the X random number memory by one address, and randomly generates the reading address of the content of the image memory.