JP2877698B2 - Partial extension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial extension device. In particular, the present invention relates to a technique for decompressing a part of JPEG-compressed data recorded on a recording medium.

[0002]

2. Description of the Related Art When displaying a part of encoded (compressed) image data recorded on a recording medium, all the compressed data is once decompressed (decoded) and then extracted and displayed. There are ways to do that. However, this method requires a long processing time.

For this reason, Japanese Patent Laid-Open Publication No. Hei 4-347781 (G.
06F15 / 66). This technique reads all compressed data recorded on a recording medium and partially decompresses only a part of the read compressed data.
However, such a decompression method cannot be simply applied to compressed image data encoded by JPEG or the like, which is encoded in block units.

In JPEG, when partial expansion of only a part of compressed data is performed, partial expansion can be performed only when this part exactly matches a block area divided by a block break.
That is, if they do not match, partial extension cannot be performed. This is because, in an encoding method such as JPEG, original image data is divided into blocks, and encoding processing is performed for each block. Therefore, it is impossible to expand the non-block area.

For this reason, for example, Japanese Patent Application Laid-Open No. 6-22151
In (H04N1 / 415), when compressing a part of the original image data, if the size of this partial area is less than an integral multiple of the processing unit block size, the size of this compressed area is Rounded up to an integral multiple.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to partially decompress a part of compressed data encoded in block units. Another object of the present invention is to partially decompress an arbitrary part of the compressed data compressed by the JPEG method.

Another object of the present invention is to provide a partial decompression device which can partially decompress an area of an arbitrary position and size in original image data even when instructed to partially decompress it. And

[0008]

A partial decompression device according to the present invention sets a partial data area to be decompressed in accordance with a divided block of original data. The partial decompression device according to the present invention compresses the original data in blocks of 8 pixels × 8 pixels by JPEG.
Reproducing means (2) for reproducing a recording medium (1) on which compressed data compressed by the data compression method is recorded, a designating means (8) for designating a decompressed area, and a decompressed area designated by the designating means (8) To a block area composed of an integer number of divided blocks of the original data (12)
A data specifying means (13) for specifying an area divided by RST including the block area in the compressed data recorded on the recording medium (1); and a data specifying means (13) for specifying the area. And a decompression means (4) for decompressing the data portion.

Further, the partial decompression device of the present invention reproduces the recording medium (1) on which the compressed data recorded by the JPEG method for compressing the original data in blocks of 8 × 8 pixels is recorded. 2), a designating means (8) for designating a decompressed area, and a decompressed area specified by the designating means (8) is composed of an integer number of divided blocks of the original data and includes an RST including the decompressed area. And a decompression means (4) for decompressing a part of the area specified by the area specification means (12, 13). I do.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

In the partial decompression device of the present invention, the area to be decompressed is set in accordance with the divided blocks of the original data. The partial decompression device of the present invention normalizes the decompressed area specified by the specifying means (8) to a block area composed of an integer number of divided blocks of the original data by the normalizing means (12).
(13, 4) specifies compressed data including the block area in the compressed data from the reproducing means (2), and decompresses this data portion.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. First, the compressed data used in this embodiment will be briefly described. The compressed data of this embodiment is a well-known JPEG (Joint Photographic Expert Groove).
up), and its compression algorithm is described in the magazine interface published by CQ Publishing Company, December 1991.
This is shown on pages 160 to 182 of the month issue.

A restart marker code (hereinafter referred to as RST) is included in the compressed data compressed by this compression method.
You can insert any number of codes. This R
ST is used to reset a predicted value of a DC coefficient in DCT transform. As a result, it is possible to prevent propagation of an error due to a transmission error of the compressed data.

That is, if a transmission error occurs in compressed data having no RST, the error propagates to the entire image after the occurrence of the error. But R
If the ST is inserted in the compressed data, even if a transmission error occurs, the propagation of the error can be suppressed to the next RST. This indicates that the RST separates the compressed data, and the blocks separated by the RST become independent partial compressed data, which can be decompressed alone.

Therefore, it is possible to partially decompress a part of the compressed data using the RST. Next, the position of the RST inserted into the compressed data will be described. FIG. 2 is a diagram illustrating an insertion position of the RST inserted into the compressed data. FIG. 2 shows the original image data before the compressed data is compressed.

In JPEG, as is well known, image data is divided into unit blocks of 8 × 8 pixels and compressed. Therefore, if the size of the image data is, for example, 10
Assuming 40 pixels × 1920 pixels, the unit block is
130 in the vertical direction and 240 in the horizontal direction for a total of 31200
Exists.

These unit blocks are one block line in the horizontal direction from the unit block at the upper left of FIG.
After the (240) processing, the processing line is lowered by one unit block, and similarly, one block line is processed in the horizontal direction from the leftmost unit block in FIG. JPE in such a procedure
When G compression is performed, the RST can be inserted after an arbitrary unit block. As shown in FIG. 2, the compressed data in this embodiment is, for each block line in the horizontal direction, that is, 240 unit blocks. It is assumed that RST is inserted and JPEG-compressed every time.

Therefore, for example, if the data from one RST position to the next RST position in the compressed data is extracted and partially expanded, the expanded data becomes the image data of one block line in the horizontal direction. That is, 8 vertical pixels × 1920 horizontal pixels. Next, the apparatus of this embodiment will be described in detail. FIG. 1 is a diagram showing functional blocks of this embodiment.

The recording medium 1 is, for example, an optical disk or a hard disk. Since this recording medium 1 is accessible in sector units, it can be read and written in sector units. This recording medium 1 stores the original image data in JP
The EG-compressed compressed data and the index information including the recording start sector address of the compressed data on the recording medium 1, the data size of the compressed data, the pixel size of the original image data (1040 vertical pixels × 1920 horizontal pixels), various flags, etc. Are recorded together.

Further, the recording medium 1 records the recording positions of all the RSTs inserted in the compressed data. That is, position information indicating the byte number of the RST from the head of the compressed data is recorded in a table format. This table is hereinafter referred to as an RST table. The reproducing unit 2 is, for example, an optical disk drive or a hard disk drive. This reproduction means 2
Is for reproducing the recording medium 1 and reading out the recorded contents.

The expansion buffer 3 is a buffer for temporarily storing the compressed data reproduced by the reproducing means 2. The expansion unit 4 expands the compressed data stored in the expansion buffer 3. The decompression means 4 performs inverse Huffman coding,
Processing such as inverse quantization and inverse two-dimensional DCT is performed to generate image data.

The storage means 5 records the image data output from the decompression means 4. The image data is stored in the display area of the storage unit 5. The video processing unit 6 extracts data from the display area of the storage unit 5 and converts the data into a video signal. The monitor 7 displays a video signal output from the video processing means 6.

The input means 8 is, for example, a keyboard or a mouse. The input means 8 receives an instruction from the operator for the device. For example, coordinate information of a decompression area indicating which part of the image is to be partially decompressed, a partial decompression operation start instruction, and the like are input. The control means 9 controls the entire device. The control means 9 starts its control in response to a partial expansion operation start instruction input from the input means 8.

The data buffer 10 stores the index information and the RST table recorded on the recording medium 1. The area determining means 11 determines whether or not the expanded area to be partially expanded input by the input means 8 is a block area composed of an integer number of divided blocks of the original image. That is, the area determination means 11 determines whether or not the extended area is a rectangular area having any two intersections among the intersections of the grid lines when the original image is divided into unit blocks as diagonal endpoints. Is determined.

The area changing means 12 is provided for the area determining means 1.
If the result of determination in step 1 indicates that the decompressed area is not a block area composed of an integer number of blocks obtained by dividing the original image, the decompressed area is changed to the block area. That is, the area changing means 12 changes the extended area to the smallest block area including the extended area.

In the case where the result of the determination by the area determination means 11 is that the decompression area is a block area composed of an integral number of blocks obtained by dividing the original image, Does not change the extension area. That is, when the expanded area is not a block area in the area determining means 11, the area changing unit 12 rounds up and normalizes the area so that the expanded area becomes a block area.

When the expanded area is just the block area, the area determining means 12
No operation is performed because the decompressed area is a block area as it is. Hereinafter, the decompressed area that has been normalized to become a block area is referred to as a normalized block area.

The data specifying means 13 includes the area changing means 12
An area necessary for decompressing (decoding) the data of the normalized block area that has been changed in step (1) is specified. That is, the data specifying unit 13 inputs the RST table from the data buffer 10 and specifies the RST position immediately before the normalized block area and the RST position immediately after the normalized block area.

The position of the RST immediately before the normalized block area is the decompression start position, the position of the RST immediately after the normalized block area is the decompression end position, Specify the data up to the end position. The frame generating means 14 is for generating a rectangular frame on the monitor 7 when the input section 8 inputs the expanded area indicating which part of the original image is partially expanded.

The frame generating means 14 is provided by the input means 8
When there is an instruction to specify the decompressed area, the frame information is output to the video processing means 6, and the video processing means 6 performs a multiplex display process and displays it on the monitor 7. The data specifying means 13 and the decompressing means 4 form compressed data including the block area in the compressed data from the reproducing means (2), and form a broadly decompressing means for decompressing this data portion. ing.

The data specifying means 13 and the area determining means 1
2 is an area specifying means for forming the decompressed area specified by the specifying means (8) by an integer number of divided blocks of the original data, and for specifying an area delimited by RST including the decompressed area. I have. The data specifying means 13, the area judging means 12, and the decompressing means 4 are associated with the decompressed area specified by the specifying means (8) and correspond to an area composed of an integral number of divided blocks of the original data. A broader decompression means for decompressing the data portion to be processed is formed.

Next, the operation of this device will be described.
FIG. 3 is a diagram showing a flowchart of the operation of this device. Hereinafter, the operation of expanding the compressed data of FIG. 2 will be described with reference to the flowchart of FIG. Now, it is assumed that reduced original image data obtained by reducing the original image data before compressing the compressed data recorded on the recording medium 1 is displayed on the monitor 7.

First, when there is a frame display instruction from the input means 8, the control means 9 controls the frame generation means 14 to generate frame information. Accordingly, the frame generating means 14
Generates frame information in the video processing means 6. The video processing means 6 performs video processing so that a rectangular frame is multiplexed and displayed on the currently displayed image, and outputs a video signal to the monitor 7.

Therefore, the reduced original image being displayed and the rectangular frame are superimposed on the monitor 7 (step S1). When the operator operates the input unit 8, the rectangular frame is
It can be freely moved on the screen, and the size of the rectangular frame can be freely changed. Further, the operator operates the input means 8 while viewing the monitor 7 on which the rectangular frame is displayed, and designates an area of the reduced original image to be partially expanded.

The control means 9 inputs information on the designated area from the input means 8 and determines the area designated by the rectangular frame based on the reduction ratio between the original image data and the reduced original image data. , Which area of the original image data corresponds to. This area calculated by the control means 9 is the area indicated by the hatched portion in FIG. In other words, this shaded area is designated as an extended area to be partially extended (step S2).

The coordinates of the upper left corner of the extended area indicated by the hatched portion in FIG. 2 are the fourth pixel from the top of the 80th vertical unit block and the 5th pixel from the left of the first horizontal unit block. Coordinates (636 pixels vertically, 5 pixels horizontally)
It is. Also, the coordinates of the lower right corner of the extension area are
The fourth pixel from the top of the unit block of the block and the horizontal 24
These are coordinates (692 vertical pixels, 1915 horizontal pixels) indicated by the third pixel from the left of the unit block of the 0th block.

Also, an instruction to start a partial decompression operation is input from the input means 8, and an instruction to start a partial decompression operation is input to the control means 9 (step S3). Next, when an operation start instruction is input from the input means 8, the control means 9 reads the index information and the RST table recorded on the recording medium 1 to the reproducing means 2, and To be stored in the data buffer 10
(Step S4).

Therefore, the index information reproduced from the recording medium 1 and the RST table are stored in the data buffer 10. Further, the control means 9 outputs the coordinate information of the decompressed area to the area determination means 11, and determines whether or not the specified decompressed area is a block area composed of an integer number of divided blocks of the original image. To determine
(Step S5).

The area judging means 11 expands the image based on the coordinate information of the expanded area and the pixel size of the original image data (1040 vertical pixels × 1920 horizontal pixels) in the index information stored in the data buffer 10. It is determined whether or not the area is the block area. That is, it operates as follows.

FIG. 2 shows a state in which original image data of 1040 pixels vertically × 1920 pixels horizontally is divided into unit blocks of 8 pixels vertically × 8 pixels horizontally. Is shown. The block area is a rectangular block having any two intersections of these grid lines as diagonal endpoints.

In other words, the block area is a rectangular block composed of an arbitrary number of continuous unit blocks when the original image is divided into a plurality of unit blocks.
Therefore, for example, a rectangular block in which the unit block of the second vertical block and the third horizontal block and the unit block of the 79th vertical block and the 238th horizontal block are unit blocks at the end points of the diagonal line has one block area. I can say.

Further, for example, a unit block of the second vertical block and the second horizontal block and a unit block of the second vertical block and the horizontal block
A rectangular block in which the ninth block is a unit block at a diagonal end point can also be said to be one block area. Therefore, the area determining means 11 is provided with the input means 8
The extension area (shaded area in the figure) designated by
It is determined whether the area is a block area.

In this case, as shown in the figure, the decompressed area is not clearly a block area, and the 80th vertical and 1st horizontal unit block and the 87th vertical and 240th horizontal block Is an area included in the block area in which the unit block is a unit block at the end point of the diagonal line. Therefore, the area determination means 11
It is determined that the extension area is not a block area.

The area determining means 11 includes an area changing means 12
Then, the determination result and the coordinate information of the extension area are output.
Further, when the area determining means 11 determines that the decompressed area is a block area, the area changing means 12 performs no processing, and executes the processing in step S7.
Move to

When the area determining means 11 determines that the decompressed area is not a block area, the area changing means 12 changes the area so that the decompressed area becomes a block area ( Step S6). The change of this area is performed as follows. The area changing unit 12 changes the extended area to a minimum block area including the extended area, which is a hatched portion in FIG.

That is, the area changing means 12 sets the extended area
It is normalized to the smallest block area that encompasses this. Therefore, the area changing unit 12 inputs the coordinate information of the decompressed area that is not a block area and outputs the coordinate information of the normalized block area that has been normalized to the data specifying unit 13.

In this case, the normalized block area that has been normalized is a unit block of the 80th vertical and 1st horizontal block and the unit block of the 87th vertical and 240th horizontal block, which are the units of the diagonal end points. It becomes a block area to be a block. Next, the data specifying unit 13 inputs the RST table from the data buffer 10, inputs the coordinate information of the normalized block area from the area changing unit 12, and outputs the compressed data from the compressed data recorded on the recording medium 1. Then, a data portion corresponding to the normalized block area is specified (step S7).

The specification of the data portion is performed as follows. The data specifying unit 13 specifies the position of the RST immediately before the normalized block area and the position of the RST immediately after the normalized block area from the RST table input from the data buffer 10. That is, the position of the RST immediately before the normalized block area is RST7 in FIG.
The position immediately after the position 9 is the extension start position.

The RST immediately after the normalized block area
Is the position immediately before the RST 87 in FIG. 2, and this position is the extension end position. In the RST table, all RST positions inserted in the compressed data are described by the number of bytes from the head of the compressed data. Therefore, the data specifying unit 13 refers to the RST table. By doing so, which data portion of the compressed data the data from the decompression start position to the decompression end position is specified.

The data specifying means 13 outputs to the control means 9 positional information of the data corresponding to the normalized block area in the compressed data. Next, the control means 9 instructs the reproducing means 2 to reproduce the compressed data obtained by compressing the original image data recorded on the recording medium 1, and the compressed data to be reproduced can be stored in the decompression buffer 3. Thus, the decompression buffer 3 is controlled.

Accordingly, the compressed data is reproduced from the recording medium 1 and stored in the decompression buffer 3 (step S8).
Further, the control means 9 instructs the decompression means 4 to retrieve the data corresponding to the data portion specified by the data specification means 13 from the decompression buffer 3 and decompress only the data of the retrieved portion. At this time, the specified data portion corresponds to the normalized block area.

Accordingly, the decompression means 4 extracts only the data corresponding to the normalized block area from the decompression buffer 3, and decompresses the data of this portion (step S9). That is, the decompression means 4 reads data from the position immediately after the RST 79 in FIG. 2 to the position immediately before the RST 87 from the decompression buffer 3, and decompresses this part of the data by inverse Huffman encoding, inverse quantization, Performs inverse two-dimensional DCT and expands the data.

Further, the control means 9 instructs to store the decompressed data decompressed by the decompression means 4 in the display area of the storage means 5. Therefore, the decompressed partial image data (the image of the portion specified by the data specifying unit 13) is stored in the display area of the storage unit 5, and is converted into a video signal by the video processing unit 6. When this video signal is output to the monitor 7, a partially expanded image is displayed on the monitor 7 (step S10).

In the above example, as shown in FIG. 2, the case where the expanded area is an area obtained by cutting the upper and lower parts of the original image has been described.
The case where the extension area is the center of the original image will be described. Hereinafter, the operation of expanding the compressed data of FIG. 4 will be described. The compressed data shown in FIG.
T is inserted. The processing of steps S1, S2, S3, and S4 in the flowchart of FIG. 3 is performed on the compressed data in which the RST is inserted for each unit block in the same manner as described above. Is specified.

Specifically, the extension area is (vertical 636).
A pixel is a rectangular coordinate area having diagonal endpoints of (pixel, 797 horizontal pixels) and (692 vertical pixels, 1597 horizontal pixels).
That is, the decompressed area is an area at the center of the original image data and is not normalized to a block area. In step S5 of FIG.
No. 1 determines that the decompressed area is not a block area, and shifts the processing to step S6.

Then, the area changing means 12 changes the decompressed area to the smallest block area including the decompressed area (step S6). The changed normalized block area is a block area in which a unit block of the 80th vertical block and the 100th horizontal block and a unit block of the 87th vertical block and the 200th horizontal block are unit blocks at diagonal end points. Become.

In step S7, the data specifying means 13 specifies data corresponding to the normalized block area thus normalized based on the RST table. In the RST table, information indicating the position of the RST inserted into the compressed data and the number of the byte inserted from the beginning of the compressed data is described, and the number of RSTs inserted into the compressed data is large. Then, the data amount described in the RST table also increases.

The data specifying means 13 outputs a horizontal block line (one vertical unit block × two horizontal blocks) in the normalized block area.
The corresponding data is specified for each (01 unit block). That is, with respect to the first horizontal block line, the expansion start position is set to the top of the 80th vertical and 100th horizontal unit blocks, and the expansion end position is set to the 80th vertical and 200th horizontal unit blocks. At the end of

For the next horizontal block line, the decompression start position is set at the beginning of the 81st block and the 100th block, and the decompression end position is set to the 81st block and the 200th block. At the end of the block. Such a process of dividing the data specifying process for each horizontal block line is performed up to the last horizontal block line in the normalized block area.

In this way, the data specifying means 13
The data in the compressed data corresponding to the normalized block area is specified. The control means 9 reproduces the compressed data from the recording medium 1 in step S8, and stores the reproduced compressed data in the decompression buffer 3. The decompression means 4 reads the data specified by the data specification means 13 from the decompression buffer 3 and sequentially performs data decompression for each horizontal block line in the normalized block area.

Therefore, the image is processed by the image processing means 6, and only the expanded area of the original image is displayed on the monitor 7. Note that, in this embodiment, the area changing means 12
Although the minimum block area including the extended area has been described as a normalized block area, the present invention is not necessarily limited to this.

For example, the area changing means 12 may set the largest block area belonging to the expanded area as a normalized block area. In other words, the unit blocks of the 81st vertical and the 2nd horizontal and the unit blocks of the 86th vertical and the 239th horizontal are divided into the diagonal end point units with respect to the extended area indicated by the hatched portions in FIG. A block area to be a block may be a normalized block area.

The area changing means 12 may set a block area simply including the extended area as a normalized block area. Further, the area changing means 12 may set a block area simply belonging to the decompressed area as a normalized block area. Further, in the above-described embodiment, if the decompressed area is not a block area, an image in which the decompressed area should be partially decompressed becomes an image of a normalized block area.

Therefore, in this case, an image in an area different from the area designated by the operator is partially expanded and displayed. Then, the control means 9 outputs the coordinate information of the extension area input from the input means 8 to the video processing means 6,
It goes without saying that the video processing means 6 may be configured to perform processing so as to mask data in a portion other than the decompressed area in the video processing and display only the image in the decompressed area.

As described above, with the masking configuration, only the image in the decompressed area specified by the operator can be output accurately. This mask processing may be performed on a normalized block area instead of the extended area. Also,
In the above-described embodiment, the operator specifies the area while viewing the reduced original image displayed on the monitor 7, and specifies the extended area. However, the present invention is not necessarily limited to this.

For example, a configuration may be adopted in which the operator inputs the coordinate information of the decompressed area with respect to the original image directly from the input means 8 without looking at the monitor 7, and designates the decompressed area. Further, in the above-described embodiment, the case where compressed data of a still image is described as the compressed data.
The present invention is not limited to this, and may be, for example, moving image compressed data or audio compressed data.

Further, in the above-described embodiment, the case where the compressed data compressed by the JPEG system is partially expanded has been described, but the present invention is not limited to this. For example, MP
The compressed data compressed by the EG method may be partially decompressed. Further, in the above-described embodiment, the case where the compressed data and the RST table are recorded on the recording medium 1 has been described. However, the present invention is not limited to this. For example, the compressed data and the RST table may be separately stored. May be recorded on a recording medium.

Further, the functional blocks of the above-described embodiments may be constituted by software or hardware as required, and it goes without saying that the present invention includes some forms. Further, in the above-described embodiment, the area is temporarily set as the normalized block area, and then the area divided by the RST is specified and partially expanded. However, this application
It is not necessarily limited to this. That is, an area that is delimited by the RST may be specified directly from the extended area. In addition, if the data is compressed data that is compressed by an encoding method in which decoding for each block can always be performed independently, it is only necessary to specify a data portion corresponding to the normalized block area, and it is necessary to specify an area delimited by RST or the like. There is no.

The above-described embodiment is merely an example of the present invention, and various changes can be made as necessary. The present invention described in the claims encompasses all such changes. Things.

[0075]

According to the present invention, the area of the partial data to be expanded is set according to the divided blocks of the original data.
Even in the case of compressed data that is data compressed in block units, it is possible to decompress data of a portion related to the decompression area specified by the specifying means (14). In addition, even if the data is JPEG-compressed data, the data of the portion related to the decompression area specified by the specifying means (14) can be expanded.

[0076]

[0077]

[0078]

[Brief description of the drawings]

FIG. 1 is a diagram showing functional blocks of an embodiment of a partial decompression device according to the present invention.

FIG. 2 is a diagram of JPEG compressed data in which RST is inserted for each line.

FIG. 3 is a diagram showing a flowchart of this embodiment.

FIG. 4 is a diagram of JPEG compressed data in which RST is inserted for each block.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Recording medium, 2 Reproduction means, 4 Decompression means, 8 Input means (designation means), 11 Area determination means (determination means), 12 Area change means (Normalization means, area specification means, decompression means), 13 Data specification means (Area specifying means, expanding means).

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06T 1/00 H04N 1/387 H04N 1/41-1/419

Claims (2)

(57) [Claims] 1. An original data is divided into a block of 8 pixels × 8 pixels.
Compressed data compressed by JPEG method
(2) for reproducing a recording medium (1) on which is recorded
When a specifying means for specifying an extended area (8), the extension area designated by the designating means (8), said original de
Area consisting of an integer number of data division blocks
A normalizing means (12) for normalizing the compressed data in the compressed data recorded on the recording medium (1).
Identify the area delimited by RST including the block area
And data specifying means (13), the identified data portion in the data specifying means (13)
Data expansion means (4).
Part extension device to do. 2. The method according to claim 1, wherein the original data is a block of 8 pixels × 8 pixels.
Compressed data compressed by JPEG method
(2) for reproducing a recording medium (1) on which is recorded
When a specifying means for specifying an extended area (8), the extension area designated by the designating means (8), said original de
Data divided into integer blocks, and
Area specifying method to specify the area delimited by RST including the area
Step (12, 13) and part of the area specified by the area specifying means (12, 13)
And a decompression means (4) for decompressing the data.
Partial extension device to be featured.