JPH01240088A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To execute an error conceal by the picture element data of other blocks by making one block of the data of a prescribed number of picture elements in a positional relation where they are not adjacent to horizontal and vertical directions, dividing it into plural blocks, transforming the picture element data orthogonally at every block and transmitting them. CONSTITUTION:A division processing circuit 2 makes one block of the data the prescribed number of picture elements in the positional relation where they are not adjacent to horizontal and vertical directions and divides it into the plural blocks concerning the picture element data for one screen shown by a picture signal f(j, k). An orthogonal transformation circuit 3 executes a two-dimensional cosine transformation at every block concerning the picture signal f(j, k) supplied from the division processing circuit 2 and supplies its factor value F(u, v) to an encoder 5 through a quantization circuit 4. Thus, when a bit error occurs in transmission data and the whole of a first block is destroyed, a reproducing system can execute the error conceal by the data of 8 neighboring picture elements to the data of a picture element (S55) of the first block.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a data transmission device that divides data of a plurality of pixels constituting a screen into a plurality of blocks, orthogonally transforms the pixel data for each block, and transmits the data. For example, it is applied to digital video tape recorders.

B. Summary of the Invention The present invention provides a data transmission device that divides the data of a plurality of pixels constituting a screen into a plurality of blocks, orthogonally transforms the pixel data for each block, and transmits the data, which are not adjacent in at least the horizontal and vertical directions. By orthogonally transforming the data of a predetermined number of pixels in a positional relationship as one block, even if a bit error occurs in the transmission system, the pixel data of the block where the bit error occurred is transferred to another block on the playback side. This allows for concealment (correction) using pixel data.

C. Conventional technology Traditionally, in data transmission systems such as digital video tape recorders, in order to suppress the redundancy of image signals, the screen is divided into blocks each consisting of a predetermined number of pixels, and the image signal is divided into blocks for each block. Transform coding is performed in which linear transformation is performed using a transformation axis that matches the special image.

Orthogonal transforms such as Hadamard transform and cosine transform are known as the above transform encoding. For example, ""'IEE
E TRANSACTIONS ON Co UN I
CAT 10NS “OL, C0M-32.NO,3,
MARC111984, pages 225-231'', in the two-dimensional cosine transformation, the process shown by the following equation is performed. Note that the original data is ■2-dimensional data f (j, k) (with blocks of (NxN) samples)
j, k = O, l, -, N-1).

N! J"Ok"O u, v=o, 1. -, N-1 D Problems to be Solved by the Invention By the way, when a screen is divided into blocks each consisting of a predetermined number of pixels and the pixel data is orthogonally transformed and transmitted for each block, for example, one block is divided into 4×4 blocks. As shown in FIG. 5, the first block is composed of 16 pixels (Sx to SIa, 5zl-5ta) indicated by O in the figure.
, Sz+~Ssa, 5al-5aa), the second block is 16 pixels (S+s~S+n+
S z s ~ S z s + S s s ~ S
j++ + S a s ~ S o), 16@element (S, 1 ~ SS4 + S61, the third block is indicated by the mouth in the figure)
〜S64+5ffl〜Sta, S□〜584), 16 pixels (S2.〜S, □S
h s ”-S b□StS~Sqs, 5g5-5
es), when pixel data is orthogonally transformed and transmitted for each block, the reproduction side reproduces the original data by performing inverse transformation processing on the orthogonally transformed pixel data for each block. For example, if a bit error occurs in the first block, all the pixel data (S+ ~ Sla, Sz + ~ Sza,
Ss+~Ssa, Sa+~544) cannot be reproduced, and the 16 pixel data of the first block indicated by O above (S+t~S14+S21~S1) cannot be reproduced.
4+S31~S:14+341~S4. ), it is difficult to conceal errors from neighboring pixel data.

Therefore, in view of the above-mentioned conventional problems, the present invention provides:
In a data transmission device that divides the data of multiple pixels that make up a screen into multiple blocks, orthogonally transforms the pixel data for each block, and transmits the data, even if a bit error occurs in the transmission system, the bit error will be corrected on the playback side. - The purpose is to be able to conceal the pixel data of a block where an error has occurred with the pixel data of other blocks.

E Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides data for a plurality of pixels constituting one screen, at least a predetermined number of pixels that are not adjacent in the horizontal and vertical directions. data division processing means for dividing the data of a plurality of pixels constituting the one screen into a plurality of blocks, with the data of the plurality of pixels as one block; a transformation encoding processing means for orthogonally transforming the pixel data for each block; and the transformation code. quantization processing means to which the coefficient values from the quantization processing means are supplied; and transmission processing means to which the output signal of the quantization processing means is supplied and outputs data at a predetermined transmission rate. do.

F. Effect In the data transmission device according to the present invention, data of a plurality of pixels constituting one screen is divided into a plurality of blocks, with data of a predetermined number of pixels located in a non-adjacent position in at least the horizontal and vertical directions being defined as one block. Then, the pixel data is orthogonally transformed and transmitted for each block.

G. Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the embodiment shown in the block diagram of FIG. 1, a sampled discrete image signal f (Lk), ie, pixel data, is supplied from a signal input terminal (1) to a division processing circuit (2).

The division processing circuit (2) processes the image signal f (j, k
) is divided into a plurality of blocks, with data of a predetermined number of pixels located in a non-adjacent position in the horizontal and vertical directions being treated as one block. In this embodiment, as shown in FIG. 2, it is assumed that one screen is composed of 64 pixels (8 x 8), and the data of each pixel located every other pixel in the horizontal and vertical directions of the screen is As a bronc, 16 pixels C5x, Sls~5sxSyy- indicated by O in the figure
Pixel data of the first block of 5qs, 5rq), 16 pixels indicated by △ in the figure (S+z, S+n to S3t,
Pixel data of the second block of 5ff4~St*, 5ys), 16 pixels (S2 +,
Szs~S4+, Sa3~S*s, 3rd of 5e1)
Bronc pixel data, 16 pixels indicated by ◇ in the figure (So, S24~S, 2.S, 4~5l16,5ll
The above image signal f is applied to the pixel data of the fourth bronc of Il).
(j, k) is divided and supplied to the orthogonal transform processing circuit (3).

The above-mentioned orthogonal transformation processing circuit (3) includes the above-mentioned division processing circuit (2).
) Regarding the image signal f(j, k) supplied from
A two-dimensional cosine transform process is performed for each block as described above, and the coefficient values F(u,v) are supplied to the encoder (5) via the quantization circuit (4).

The encoder (5) outputs data representing the coefficient values F(u,v) quantized by the quantization circuit (4) from the signal output terminal (6) at a predetermined transmission rate.

That is, in the data transmission device of this embodiment, data of a predetermined number of pixels located in a non-adjacent position in the horizontal and vertical directions is regarded as one block, and a plurality of pixels (S8. to S, 1ll) constituting one screen are The data is divided into multiple blocks such that the pixels of each block are located in a square grid pattern, and the pixel data is cosine-transformed and transmitted for each block.

By performing data transmission in this way, for example, if a bit error occurs in the transmitted data and the entire first block is destroyed, the reproducing system will
), 8 neighboring pixels (Saa, Se2.Sa
Error concealment using each data (b, Ssa, Ssh, Sba, 5b5-5bb) can be performed as follows.

(1) Second. When there is no error in the third and fourth blocks: Each of the above pixels (Sas+S4s+Sga+Ssa+SS
&1S641S6SIS66) can be used to perform error concealment of the data of the pixel SSS.

(2-1) There are no errors in the second and third blocks,
If the entire fourth block is destroyed, each pixel of the second and third blocks (545°5651S541SS
The above error concealment can be performed using the four data of &).

(2-2) There are no errors in the second and fourth pronks,
If the entire third block is destroyed, each pixel C3sa of the second and fourth blocks.

The above error concealment can be performed using six data: Ssb, Saa, Ssb, Sba, 5b6).

(2-3) There are no errors in the third and fourth blocks (,
If the entire second block is destroyed: Each pixel of the third and fourth blocks (545°Shs+Saa+Sa
The above error concealment can be performed using the six data (h+Sba+5bh).

(3-1) When there is no error in the second block and the entire third and fourth blocks are destroyed: Conceal the error using the two data of each pixel (Ssa, 5si) in the second block. It can be carried out.

(3-2) If there is no error in the third block and the entire second and fourth blocks are destroyed, use the two data of each pixel (545, 565) of the third block to conceal the error. It can be performed.

(3-3) When there is no error in the fourth block and the entire second and third blocks are destroyed: 4 of each pixel (S4a, Sab, Sba, 5hh) in the fourth block
The above error concealment can be performed using the data.

In addition, in the data transmission device of this embodiment, the data of a predetermined number of pixels located in a positional relationship that is not adjacent to each other in the horizontal and vertical directions is regarded as one block, and the data of a plurality of pixels constituting one screen are divided into pixels of each block. Although the pixel data is divided into a plurality of blocks arranged in a square grid, and the pixel data is cosine-transformed and transmitted for each block, the present invention is not limited to the above-mentioned embodiments. As shown in FIG. ), the error concealment ability on the playback side can be improved even if an orthogonal transform such as Hadamard transform other than the above-mentioned cosine transform is performed.

H Effects of the Invention In the data transmission device according to the present invention, one block is data of a predetermined number of pixels that are not adjacent to each other in at least the horizontal and vertical directions, and data of a plurality of pixels constituting one screen is divided into multiple blocks. Since the pixel data is orthogonally transformed and transmitted for each block, even if a bit error occurs in the transmission system, the playback side performs an orthogonal transform on the pixel data of the block where the bit error occurred on the playback side. Error concealment can be performed using pixel data.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a data transmission device according to the present invention, FIG. 2 is a schematic diagram showing an example of distribution of data of a plurality of pixels constituting one screen to each block in the data transmission device 3 is a schematic diagram showing another example of distribution of data of a plurality of pixels constituting one screen to each block in the data transmission device, and FIG. 4 is a schematic diagram showing another example of distribution of data of a plurality of pixels constituting one screen in the data transmission device. FIG. 7 is a schematic diagram showing still another example of distribution of data to each block. FIG. 5 is a schematic diagram showing an example of distribution of data of a plurality of pixels constituting one screen to each block in a conventional data transmission device. 1... Signal input terminal 2... Division processing circuit 3... Encoding processing circuit 4... Quantization processing circuit 5... Encoder 6...Signal output circuit Sll-5lll+...Pixel

Claims (1)

[Claims] Regarding the data of a plurality of pixels constituting one screen, one block is data of a predetermined number of pixels that are located in a positional relationship that is not adjacent to each other in at least the horizontal and vertical directions. a data division processing means for dividing pixel data into a plurality of blocks; a transformation encoding processing means for orthogonally transforming the pixel data for each block; and a quantization processing means to which coefficient values from the transformation encoding processing means are supplied. and a transmission processing means that is supplied with the output signal of the quantization processing means and outputs data at a predetermined transmission rate.