JPS628661A - Picture compressing device - Google Patents

Abstract

PURPOSE:To use in common the hardwares of both means by changing over a present picture compressing method and a compressing method effective to a very long run length by an action mode designation. CONSTITUTION:In an MH converting part in a picture compressing part, a changing point detecting part 25 detects the changing point of a picture data 20, and sends a detecting signal 29 to a run length counter 26 and an MH code output part 28. A makeup overflowing detecting part 27, when an action mode signal 21 is 0 and a counter value 30 comes to 2560, sends a detecting signal 31 to the MH code output part 28 and the counter 26, and when the signal 21 is 1 and the counter value 30 comes to 2623, sends the signal 31. The MH code output part 28, when the signal 21 is 0, outputs the makeup code of a run length 2560, and when the signal 21 is 1, sends the makeup code of a run length 2560, a run length 63 and the terminating code of a run length 0 of the present opposite color continuously.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to an image compression device.

[Background of the invention]

For image compression methods that comply with the CCITT Draft Recommendation, -
For the dimension compression code, a terminating code with a run length of 0 to 63 bits and a make-up code with a run length of 64 to 2560 bits are defined.A run length of 0 to 63 is encoded with only a terminating code,
A run length up to 2560 initially has a make-up code representing a run length equal to or shorter than that run length, and a terminus representing the difference between the actual run length and the run length represented by the make-up code. It is encoded using a coding code. According to this draft recommendation, the maximum flame expressed as one run length is 2623 (2560 + 65).
Becomes a bit.

When considering the encoding of extremely long run lengths (2624 bits or more) due to larger and higher definition images in the future, it will be easier to encode images using a pair of one makeup code and one terminating code. A method of encoding with two or more makeup codes and then encoding with one terminating code is considered effective.

[Purpose of the invention]

The purpose of the present invention is to improve the current image compression method of encoding with one make-up code and one terminating code, and to improve the effective compression for very long run lengths (for example, 2624 bits or more) that will be considered in the future. By providing a means for using both methods, it is possible to standardize the software for both methods.

[Summary of the invention]

In order to achieve the above object, the present invention includes a means for controlling image compression, memory address management, and image compression operation, and a means for controlling the image compression operation, which actually executes image compression, and has an operation mode register therein. , a run length counter, and a compression code converter.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an image compression device showing one embodiment of the present invention. In FIG. 1, 1 indicates start-up, 8 indicates shift control parameters, and 9 indicates operation mode information. 2. DM
When the AC receives the activation signal from the host device, it stores the operation mode, image information start address, image information data number, code output canister start address, and the like from the image information storage memory.
'8. To take in the code output Canilia space number and shift the picture filter and code data. It calculates the shift control parameters and outputs them to the image compression unit along with the operation mode information.

Next, after starting the 2nd process for the five-image compression section,
& Wait for READ-WRITE request signal, and 6. When a READ-WRITE request signal is received, READ is executed with the image information storage memory.
- Performs WRITE access processing, image and compression code one-image information storage memory address management, and processing completion check.

The engineering image compression section is 2. Receives the Z processing start signal from Otori c,
An image compression operation is performed using the configuration shown in FIG.

In FIG. 2, 182 image data are stored in 5. After being set in the French read data buffer via the data bus, 14. Parallel (P) → Series (
S) Converted and output as 1-bit serial data 15.
ME (input to the converter).

15. The MH conversion unit includes 12. clock control section and 10
゜Under the control of the operation mode register, convert the 2Q image data into 2iMH code data, 16. Series (S) →
Send to parallel CP) converter and set to 1z write data buffer.

10. The operation mode register is 2. 15. Receive and receive the 2 operation mode information. The operation mode signal 2 is output to the MH converter.

12. The clock control section first consists of 2. 8 from rmc. 2. Receive shift control parameters and set initial value states for all shift controls of the five image compression units;
The I L READ - WRITE signal is received from above, starts the operation of each unit of the image compression section, and controls the shift clock of each unit.
A 19READ-①ITE request set signal is sent to the request control circuit.

1tlAD-■ITE request control circuit performs 12. From the clock control section, 19. 2. Receive the READ-WRITE request set signal; Sends & section D ITE request signal to mc.

As described above, the image compression apparatus of this embodiment uses the information in the image information storage memory to determine whether 2, ImC, or 3.
1 After setting the initial value and operation mode for the image compression unit and starting processing, press the READ button of the image compression unit.
-According to the WRITE request, the processing is executed at high speed, and the processed image compression unit 2. Under the control of Otori C, it is a device that performs high-speed conversion.

Next, FIG. 3 shows the logical configuration of the 15° ■ conversion section in the & image compression section, which is a feature of the present invention, and its operation will be explained.

As shown in FIG.
26 run length counter, 27. Make-up overflow detection section, 28. It consists of an MH code output section.

The 21 operation mode signal is output from the 1α operation mode register to the 21 make-up output and the barflow detection unit, 28. M
It is given to the H code output section. Next, the 2α image data is
25 is given to the change point detection section in synchronization with the 2z clocked control signal. 25. When the change point detection unit detects the change point of the 21 image data, the change point detection unit detects the change point of the 21 image data. The change point detection signal is sent to the 26 run length counter and the MH code output section 28.

26. The run length counter is 22. 25. Start run length counting in synchronization with the clock control signal;
When the 29 change point detection signal is received from the change point detection section, the counting operation is stopped and this state is maintained. Also, when the 3t make-up output barflow detection signal comes, clear the run length count value and 29. Counting continues until the change point detection signal arrives.

The 21 make-up output barflow detection section sends the 2B, MH code output section and 26.Send 2 to the run length counter.Also, if the operation mode signal is 111, 30.Send the run length counter value to 2625 (2
560+65), a 31 overflow detection signal is sent to the 2B, MH code output section and the 26 length counter.

When the 2B and MH code output section receives the 31 overflow detection signal, it outputs 2 when the operation mode signal is 101.
A make-up code with a run length of 2560 is output.

Further, when the operating mode No. 45 is 11 m, a make-up code with a run length of 2560, a terminating code with a 2-in length 63, and a terminating code with a run length 0 of the current opposite color are successively output. And 30. Continuously output the acknowledgment code corresponding to the run length counter value and finally 12. For the clock control section, 2
4. Sends the MH code output end signal. 12. The clock control section outputs the 2z clock control signal again to detect the next image change point.

When the above operation is performed, for example, when converting the run length of white 3000 bits, if the operation mode is 101, white makeup 2560 + white makeup 384
+white terminating 56, and the makeup code is continuously output. Also, it works.

In the case of -do 11'', white makeup 2560 + white terminating 63 + black terminating 0 + white makeup 520 + white terminating/g 57, and the white 30000 run length is one makeup with black terminating 0 in between. It is divided into an up code and one terminating code.

〔Effect of the invention〕

As described above, according to the present invention, there is provided a means for dividing a run length exceeding 2623 bits into one make-up code and one terminating code by specifying an operation mode, and a means for continuously outputting the make-up code. , a means for outputting one terminating code can be used, and hardware can be made common.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an image compression device according to an embodiment of the present invention, FIG. 2 is an internal configuration diagram of an image compression section, and FIG. 3 is a characteristic of the present invention. image compression section,
4... Address bus, 5... Data bus, 7
...Processing start activation signal, 9...Operation mode information, 1
0... Operation mode register, 12... Clock control unit, 13... Read data buffer, 17... Write data buffer, 18... Image data, 20... Input image data, 21... - Operation mode signal, 25... Changing point detection section, 29... Changing point detection signal.

Claims (1)

[Claims] 1. In a device that compresses image data using the MH method, there is a memory that stores image information and compression codes, and a direct memory that controls read/write of image information to the memory, and controls the memory address management and image compression operation. It consists of a memory read control device and an image compression section that receives a start signal from the direct memory read control device and actually executes image compression. An image compression device characterized in that it is possible to specify division into two make-up codes and a terminating code.