JPH0244965A - Picture output device - Google Patents

Abstract

PURPOSE:To attain a high speed picture output by converting a compressed data of an input picture into a compressed data of a reduced picture directly not through the processing to be restored to an image data and restoring and displaying the compressed data into the image data in the unit of picture elements. CONSTITUTION:The compressed data 1 of an input picture is converted into a compressed data 3 of a reproduced picture by a reduction conversion processing circuit 2. Since the conversion processing is a processing to convert the compressed data 1 into the compressed data 3 directly without expanding the compressed data 1 into the image data, the processing is executed at a high speed. The compressed data 3 obtained by the reduction conversion processing is transferred to an expansion circuit 4, restored into the image data 5 and displayed on the screen of a CRT unit 7 as a pattern. Thus, the time from the input of the compressed data of the picture to the output is reduced and a fast speed picture output is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image output device that displays or prints an image input as compressed data.

Conventional technology In electronic file systems, images such as documents are stored as compressed data on recording media such as optical disks, but in order to display or print the stored images, the compressed data must be restored into pixel-by-pixel image data. There is a need to. In addition, in general, the number of pixels in the stored document is greater than the number of pixels in the output image (due to the difference between the document reading resolution and output resolution, and the difference between the document original size and output size).
It is also necessary to perform image reduction processing.

Conventionally, as shown in FIG. 3, a device for displaying such an image restores compressed image data 21 to pixel-by-pixel image data Z3 using a decompression circuit 22, and converts this into pixel and line data Z3 using a reduction circuit 24. By thinning processing etc., the image data 5 is reduced to J: which matches the number of display pixels,
The configuration was such that this was displayed on the screen of the CRT unit 27 under the control of the CRT controller 26.

The configuration of the device that prints out images is also CRT Cornino l.
-27 cuffs! , lntaunisoto, CRT controller 26
It was the same, except that it became a printer controller.

Problems to be Solved by the Invention However, with this configuration, there is a problem in that it takes a long time from when compressed image data is input until it is displayed or printed.

This is because the processing for each reduction circuit is a bit-by-bit processing, but since the number of bits of the image data to be processed is extremely large, it takes a long time to process, and such image data is not transferred from the decompression circuit 22. This is because it takes a long time to transfer the data to the reduction circuit 24.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image output device that can shorten the time from input to output of compressed image data.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention converts compressed image data into compressed image data by direct processing (that is, by processing the compressed data itself without restoring it to image data). The apparatus is provided with a means for decompressing the compressed image at a stage upstream of the decompressing means, and the decompressing means decompresses the compressed data of the reduced image into image data to be finally output.

As mentioned above, compressed data, which has a much smaller amount of data than image data, is directly converted into compressed data of a reduced image, so the time required for the conversion process is the same as that of restoring the compressed data of the input image. The time required for image reduction by bit processing of image data can be significantly reduced.

Further, since the restoration process is performed on the compressed data whose number of pixels has been reduced through such conversion process, the processing time is shorter than when the compressed data before the reduction process is restored. Also,
Since the image data to be restored has already been reduced, the amount of data is smaller than before reduction, and the transfer time is also shortened.

Therefore, the time from inputting compressed image data to outputting (displaying or printing) it is significantly shorter than in the past, and high-speed image output is possible.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows an image display device 5 according to an embodiment of the present invention.
FIG. In the figure, 1 is compressed data of an image input from the outside, 2 is a reduction conversion circuit that converts compressed data 1 into compressed data of a reduced image by direct conversion processing, and 3
is the compressed data after this reduction conversion. 6 is a decompression circuit that restores compressed data to pixel-by-pixel image data, 5 is the restored image data, and 6 is a C.
This is a CRT controller that displays on the RT unit 7.

In the above configuration, input image compressed data 1 is converted into reduced image compressed data 3 by the reduction conversion processing circuit 2. This conversion process is performed on the compressed data 1 as described later.
This process can be executed at high speed since it is a process of converting directly into compressed data 3 without expanding it into image data.

Compressed data 3 obtained through this reduction conversion process is transferred to an expansion circuit 4 and restored to image data 5. This restoration process may be the same as before, but the input compressed data 3
Since the image data 5 has already been reduced, the number of pixels of the image data 5 is reduced, and the restoration processing time is shortened accordingly, and the time for transferring the image data 6 to the CRT controller 6 is also shortened.

In this way, the image data 5 of the reduced image corresponding to the compressed data 1 is obtained at high speed and transferred to the CRT controller 6.
The image is transferred to the CRT unit 7 and displayed as an image on the screen of the CRT unit 7 under its control.

FIG. 2 is a block diagram showing an example of the reduction conversion circuit 2. As shown in FIG. Here, it is assumed that the compressed data 1 is encoded using the "'2-line short run length encoding method 2" which is used for recording optical discs. This encoding method simultaneously processes two consecutive odd-numbered scanning lines and even-numbered scanning lines as one frame, observes the current focus and the previous 2x2 bits on each line, and calculates the transition code, run code, This is a method of encoding by directly combining codes, but since it is well known, detailed explanation will be omitted.

In Fig. 2, 11 is a buffer circuit for temporarily accumulating compressed data 1, and 12 is a buffer circuit for detecting flags, transition codes, and dummy bits in compressed data 1. Or it is a detection circuit that detects the edge of a page. Reference numeral 13 denotes a control circuit that controls each section according to the detection output of the detection circuit 12.

The run code and direct code in the compressed data stored in the buffer circuit 11 are distributed to a run code processing system and a direct code processing system, respectively, under the control of the control circuit 13. In this encoding method, each line of the image always starts with a white run code, so the first code of each line is sent to the run code processing system, and subsequent run codes or direct codes are inserted before it. The transition code is sent to the corresponding processing system according to the type of transition code.

The run code processing system includes a hexadecimal conversion circuit that converts the run code into hexadecimal data, a division circuit 15 that divides this hexadecimal data by a constant corresponding to the reduction ratio of the image, and a division circuit 15 that divides the hexadecimal data by a constant corresponding to the image reduction ratio.
The encoder 1G encodes the quotient data (hexadecimal data) outputted from the encoder into a run code, and the remainder correction circuit 17. The direct code processing system includes a frequency dividing circuit 18 that divides the direct code at a frequency division ratio corresponding to the reduction ratio, and the remainder correction circuit 17.

Reference numeral 19 denotes an output circuit that orders the run code input from the encoder 16, the direct code input from the frequency dividing circuit 18, and the transition code input from the control circuit 13 and sends them to the outside. Note that the output circuit 19 adds flags to each frame and inserts necessary dummy bits.

The operation of this reduction conversion circuit 2 is as follows. When a run code is input, it is converted into hexadecimal data by a hexadecimal conversion circuit 14 and then divided by a division circuit 15. The quotient data is the length after reduction, which is converted into a run code by the encoder 16 and sent to the outside from the output circuit 19. On the other hand, the direct code is frequency-divided by the frequency dividing circuit 18 into a direct code having a length corresponding to the run length after reduction, and this is output to the output circuit 19.
It is sent to the outside. Further, the transition code between each code is sent out from the 11 output circuit 19.

Note that the remainder correction circuit 17 calculates the remainder output from the division circuit 15 or the frequency division circuit 18 for each code.
-7 Performs control to correct the next code in one go.

That is, if the next code is a run-length code, the remainder data is added to the dividend data of the division circuit 16 as hexadecimal data. On the other hand, if the next code is a direct code, a "'0" signal with the number of bits equal to the remainder data is input to the frequency dividing circuit 18.

1. In order not to lose the information of the thin line on the input image, the division circuit 15 outputs 1 when the quotient is less than 1. Similarly, the frequency dividing circuit 18 outputs a run code with a minimum run length of 1.

The compressed data 3 of the reduced image obtained in this way is data of the same encoding method as the compressed data 1. Therefore, the decompression circuit 4 may be similar to a conventional decompression circuit using the same encoding method.

Note that by replacing the CRT unit 7 in this embodiment with a printer unit and the CRT controller 6 with a printer controller, an apparatus that prints out images can be realized.

Further, even in the case of compressed data by other encoding methods that can be subjected to similar direct reduction conversion processing, the present invention is similarly applicable.

Effects of the Invention As is clear from the above explanation, the present invention directly converts compressed data of an image input from the outside into compressed data of a reduced image without going through the process of restoring it to image data. Since the data is restored to pixel-by-pixel image data for display or printing, the processing time for reduction, processing time for restoration, and image data transfer time are all shorter than before, and the image output is faster. This has the effect of increasing speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an image display device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of the configuration of the reduction conversion circuit in FIG. 1, and FIG. 3 is a schematic diagram of a conventional image display device. FIG. 1... Compressed data of input image, 2... Reduction conversion circuit,
3... Compressed data of reduced image, 4... Decompression circuit, 5
...Image data of reduced image, 6..CRT controller, 7..CRT unit.

Claims (1)

[Claims] means for directly converting compressed data of an image inputted from the outside into compressed data of a reduced image and outputting the compressed data; means for restoring the compressed data inputted from this means into pixel-by-pixel image data and outputting the compressed data; An image output device comprising means for displaying or printing image data as an image.