JPH05183754A - Picture display device - Google Patents

Abstract

PURPOSE:To restore a picture which is made into a high efficiency code with a small and simple processing circuit in a short time by extracting only DC component data from compression data and representing a luminance level for one block by means of the luminance level which can be obtained by means of the DC component data. CONSTITUTION:When the outline of the picture which is photographed by a user with an electronic camera, etc., is recognized at the spot, a picture data decoder 10 reads out compression data S11 from a memory card 11 where the photographed picture is made into the high efficiency code so as to be recorded. Then, the picture data decoder 10 picks out DC coefficient data S12 at every block area from coefficient data S11 which is inputted at every block area, decodes representative value data by successively making the DC coefficient data S12 pass through a DC component decoding means 13 and a data integrating means 14 and interpolates representative data S14 of the block area based on representative value data of the adjacent block. The operation is widely adapted at the time of constituting the respective blocks by the nXn picture elements (n=1, 2,...).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an image display device,
It is particularly suitable for application to the case where an original image is restored from still image data that has been encoded with high efficiency using a simple decoding device.

[0002]

2. Description of the Related Art Conventionally, in a coding method in which a still image is highly efficiently coded and transmitted through a transmission line, still image data is discretized cosine transformed (DCT).
It has been proposed to perform osine transform) for encoding.

That is, when the discrete cosine transform circuit 1 orthogonally transforms the image data S1 into the coefficient data S2, the coefficient data S2 is quantized into the quantized data S3 via the quantizing circuit 2, and the variable length coding circuit 3 is further quantized. The image is highly efficiently encoded by compressing the data via (FIG. 3).

Here, the discrete cosine conversion circuit 1
Divides the image data S1 into blocks of 8 × 8 pixels,
The pixel data of 64 (8 × 8) is two-dimensionally DCT-converted into the coefficient data S2 of 64 (8 × 8).

Here, of the 64 coefficient data S2, the upper left coefficient data corresponds to the DC component, and the remaining 63 coefficient data corresponds to the AC component (FIG. 4). The variable length coding circuit 3 inputs the quantized data S3A corresponding to the DC component of the quantized coefficient data S2 to the DC component Huffman coding circuit 4 and the quantized data S3B corresponding to the AC component as the AC component. It is adapted to be input to the Huffman encoding circuit 5.

Here, the DC component Huffman coding circuit 4 is
After obtaining the difference between the quantized data S3A and the DC coefficient data one block (8 × 8 pixels) before, Huffman coding is performed, and the compressed data S4A is output, and the AC component Huffman coding circuit 5 outputs 63 pixel data. Quantized data S3
B is zigzag scanned, rearranged, Huffman-encoded, and output as compressed data S4B.

[0007]

By the way, when the original image is decoded from the compressed data S4 encoded in this way, the processing procedure is the reverse of that at the time of encoding, that is, as shown in FIG. The data S4A and S4B are sequentially decoded through a variable length inverse encoding circuit 6, an inverse quantization circuit 7 and a discrete cosine inverse conversion circuit 8 to decode an original image.

However, if such a decoding device is to be realized by hardware, the device becomes large, and if it is to be processed by software, the processing time is several tens of minutes. Therefore, if it is sufficient to confirm what kind of scene was shot, for example, if you want to check the recorded image taken outdoors using an electronic camera, the portability and processing time It was not suitable in terms of.

Further, for example, when it is desired to select only the image at the moment of the goal from a plurality of still images continuously shot to take the moment of the goal of the track competition and transmit the corresponding image data, the decoding device similarly The large size and the long processing time are inconvenient for the user.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose an image display device capable of easily restoring and displaying a highly efficient coded still image.

[0011]

In order to solve such a problem, in the present invention, an image is divided into a plurality of block areas each having a predetermined number of pixels, and the pixel data of each block area is orthogonally transformed. In the image display device 10 that sequentially decodes and displays the coefficient data S11 input from the output orthogonal transform encoding means, the DC coefficient data S12 corresponding to the DC component determined for each block area is extracted from the coefficient data S11. Coefficient data extraction means 12 and DC component decoding means 13 for decoding the DC coefficient data S12 extracted from the DC coefficient data extraction means 12.
And a data integration means 14 for integrating the decoding coefficient data S13 decoded by the DC component decoding means 13 and outputting representative value data S14 representative of all pixels forming each block area, and representative value data of each block area. S14 is the representative value data S14 of the block area adjacent to the block.
And a data interpolating means 15 for interpolating based on the above and outputting as the interpolated representative value data S15.

[0012]

[Function] Coefficient data S input for each block area
11, the DC coefficient data S12 is extracted for each block area, the representative value data S14 is decoded by sequentially passing the DC coefficient data S12 through the DC component decoding means 13 and the data integration means 14, and the representative value data S14 of the block area. Is interpolated based on the representative value data S14 of the adjacent block, the transmission image can be decoded in a short time by a small and simple processing circuit. As a result, when portability is required or when it is desired to grasp the outline of the original image in a short time, it is possible to further improve the usability as compared with the conventional case.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 10 indicates an image data decoding device as a whole, which is adapted to input the compressed data S11 read from the memory card 11 to the DC component extraction circuit 12. Here, the DC component extraction circuit 12 extracts only the DC component data S12 corresponding to the DC coefficient data from the 64 pixel data composed of one DC coefficient data and 63 AC coefficient data per block. ,
It is adapted to be supplied to the inverse Huffman coding circuit 13.

The inverse Huffman coding circuit 13 decodes the compressed data S12 into the DC difference coefficient data S13 and outputs it to the integrating circuit 14 by the processing procedure reverse to that at the time of coding. The DC coefficient data representing each block is decoded by obtaining the sum of the blocks and supplied to the interpolation circuit 15 as the representative value data S14.

The interpolation circuit 15 divides the representative value data S14 into luminance levels of black and white 8 gradations to obtain the luminance data S15, and also determines the luminance levels of all 64 (8 × 8) pixels forming one block. As a representative of S15, the output is made to the monitor 16. Here, the monitor 16 displays all the pixels of each block as an image represented by a brightness level of black and white 8 gradations determined based on the brightness data S15.

In the above configuration, when the user wants to check the outline of the image taken by the electronic camera or the like on the spot, the image data decoding apparatus 10 uses the memory card 11 in which the taken image is recorded with high efficiency coding. Compressed data S11
Read out. Subsequently, the image data decoding apparatus 10 extracts only the DC component from the compressed data S11 through the DC component extraction circuit 12, converts the DC component into the representative value data S14 through the inverse Huffman coding circuit 13 and the integration circuit 14, and then interpolates. The circuit 15 outputs the interpolated representative value data S15 obtained by interpolating the representative value data S14 to the monitor 16.

Here, the monitor 16 is, for example, usually 768 ×
The display screen displayed with 480 pixels is reduced in resolution to 96 × 60 pixels, and the brightness of each pixel is displayed as an image showing black and white 8 gradations.

With the above arrangement, the image data decoding apparatus 10 extracts only the DC component data S12 from the compressed data S11, and the luminance level S15 obtained by the DC component data S12 represents the luminance level of one block. This makes it possible to downsize the hardware, which had to be large for processing the AC coefficient data, and reduce the processing time because the processing is not performed, which requires portability and immediacy. Immediately in memory card 11
The image stored in can be easily confirmed.

In the above embodiment, the case where the still image is decoded by using the hardware of the image data decoding device 10 has been described, but the present invention is not limited to this.
For example, as shown in FIG. 2, the memory card 11 is provided in the main body 21 of the portable computer device in which the processing program corresponding to the processing procedure by the image data decoding device 10 is activated.
May be inserted, decrypted, and displayed on the liquid crystal display 22.

In the above embodiment, the case where the still image data is read as the compressed data S11 from the memory card 11 has been described, but the present invention is not limited to this, and the still image data is read from the magnetic recording medium or the magneto-optical recording medium. It can also be widely applied to read out.

In the above embodiment, the interpolation circuit 1
5 describes the case where the luminance level of the entire block determined by 8 × 8 pixels is identically interpolated and output based on the representative value data S14 determined by the decoded DC component data S12, but the present invention is not limited to this. For example, the brightness level S15 of the block located at the center may be interpolated based on the representative value data S14 of the adjacent blocks that are vertically and horizontally adjacent to each other.

Furthermore, in the above-mentioned embodiment, the case where each block is composed of 8 × 8 pixels has been described, but the present invention is not limited to this, and it is composed of n × n pixels (n = 1, 2, ...). It can also be widely applied when doing.

[0024]

As described above, according to the present invention, the DC coefficient data is extracted from the coefficient data orthogonally transformed for each block area, and the DC coefficient data is decoded through the DC component decoding means and the data integration means in sequence. Then, by decoding the data into representative value data, interpolating based on the representative value data in the block area and outputting the data, a highly efficient coded image can be obtained in a short time using a processing circuit that is much smaller than before. Can be decrypted in time. As a result, when portability is required or when it is desired to immediately grasp the outline of an image in a short time, the usability for the user can be further improved compared to the conventional case.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an image display device according to the present invention.

FIG. 2 is a schematic diagram for explaining an image display device according to another embodiment.

FIG. 3 is a block diagram provided for explaining an image encoding device.

FIG. 4 is a schematic diagram for explaining a DC coefficient component and an AC coefficient component.

FIG. 5 is a block diagram for explaining a conventional image data decoding device.

[Explanation of symbols]

10 ... Image data decoding device, 11 ... Memory card,
12 ... DC component extraction circuit, 13 ... Inverse Huffman coding circuit, 14 ... Integration circuit, 15 ... Interpolation circuit, 16 ...
Monitor, 21 ... Computer device body, 22 ... Liquid crystal display.

Claims (1)

[Claims] 1. An image is divided into a plurality of block areas each having a predetermined number of pixels, and pixel data of each block area is orthogonally transformed and the coefficient data input from an orthogonal transform coding means for outputting the data is sequentially added. In an image display device for decoding and displaying, among the coefficient data, a DC coefficient data extracting means for extracting DC coefficient data corresponding to a DC component determined for each block area, and the DC extracted by the DC coefficient data extracting means. DC component decoding means for decoding coefficient data, data decoding means for integrating the decoded coefficient data decoded by the DC component decoding means, and outputting representative value data representative of all pixels forming each block region, Interpolate the representative value data of each block area based on the representative value data of the block area adjacent to the block,
An image display device, comprising: a data interpolation means for outputting as interpolation representative value data.