KR100808501B1 - Image processing apparatus and processor for devision decoding and control method thereof - Google Patents

Abstract

The present invention relates to an image processing apparatus, a processor, and a control method thereof for split decoding a jpeg file. According to the present invention, a method of controlling a jpeg file decoding using a camera control processor having a low capacity memory is provided. Identifying a restart marker of the jpeg file; (b) partitioning the jpeg file based on the identified restart marker; And (c) synthesizing the raw images decoded by the camera control processor. According to the present invention, there is an advantage in that a high capacity / high resolution jpeg file can be decoded even when a low capacity CCP memory is used.

Restart Marker, CCP, Memory, Size, Split, Synthesis

Description

IMAGE PROCESSING APPARATUS AND PROCESSOR FOR DEVISION DECODING AND CONTROL METHOD THEREOF}

1 is an internal block diagram of an image processing apparatus according to a preferred embodiment of the present invention.

2 is a block diagram of a decoding control processor in accordance with a preferred embodiment of the present invention.

3A to 3B show a map structure of a CCP memory according to the present invention.

4A-4B show raw image accumulation results in accordance with the present invention;

5 is a diagram illustrating a division decoding process according to an embodiment of the present invention.

6 is a diagram illustrating a division decoding process according to another embodiment of the present invention.

The present invention relates to an image processing apparatus, a processor, and a control method thereof for split decoding a JPEG file. More particularly, the present invention relates to a high capacity / high definition JPEG file in a device including a camera control processor of a low memory. An image processing apparatus, a processor, and a control method thereof.

Recently, digital cameras are rapidly evolving due to the high integration of image sensors such as Charged Coupled Device (CCD) sensors and Complementary Metal Oxide (CMOS) sensors and the processing of digital images. It is the situation that is attached.

Although users may store captured images through an image sensor mounted on a mobile device, an increase in the system memory size of a mobile device frequently causes an image stored in a device such as a computer to be stored on a mobile device.

In general, an image file is stored in an encoded state so that the file storage and transmission process can be efficiently performed. The JPEG format is the most widely used graphic file format because of its high compression efficiency.

JPEG is a standard for image compression set by the Joint Photographic Experts Group.

When the image file is compressed in the JPEG format, the user needs to decode the JPEG file in order to check the JPEG file stored in the mobile.

In general, in a miniaturized device such as a mobile, image control is performed through a camera control processor.

The camera control processor receives and stores the JPEG file from the system memory of the mobile when decoding the specific JPEG file, and includes a low-capacity memory (hereinafter referred to as 'CCP memory') for storing the decoded raw image. do.

The inclusion of low capacity memory in the camera control processor is because the manufacturing cost of the camera control processor depends on the memory size, and thus the conventional CCP memory has a capacity of about 128K or 256K bytes.

In order for the camera control processor to properly decode, the size of the JPEG file and the raw image decoded must be smaller than the size of the CCP memory. Otherwise, the camera control processor cannot decode.

When capturing an image using an image sensor mounted on the mobile, there is no problem because the size of the captured image is input considering the size of the CCP memory, but as described above, when the image stored in the computer is downloaded and decoded. Can cause problems.

For example, if the CCP memory is 256K bytes and the JPEG file downloaded from the computer is 500K bytes, the JPEG file is stored in the mobile's system memory but the camera control processor decodes the JPEG file due to lack of CCP memory capacity. A problem arises that cannot be performed.

In addition, as in the related art, when the low-capacity CCP memory is used, decoding may not be performed because of the resolution set for the JPEG file as well as the size of the JPEG file itself.

The conventional camera controller processor has a resolution of approximately 400x320. If a JPEG file downloaded from a computer is set to a resolution of 680x480, which is a VGA (Video Graphic Adapter) resolution, the raw image is RGB 16-bit information per pixel. Includes requires at least 600K bytes of CCP memory capacity to decode the corresponding JPEG file.

However, as described above, since the general CCP memory has 128K or 256K bytes, there is a problem that the conventional CCP memory cannot decode the high-resolution JPEG file.

If the decoding is not performed as described above, a problem occurs in compatibility between the computer and the mobile.

However, there is an unacceptable problem because increasing the capacity of the CCP memory increases the manufacturing cost of the camera control processor.

In order to solve the problems of the prior art as described above, an object of the present invention is to propose an image processing apparatus, a processor, and a control method thereof, which can decode a high-capacity jpeg file using a low-capacity CCP memory.

Another object of the present invention is to provide an image processing apparatus, a processor, and a method of controlling the same, capable of decoding a high resolution JPEG file using a low capacity CCP memory.

In order to achieve the above object, according to a preferred embodiment of the present invention, a method for controlling the decoding of a JPEG file using a camera control processor having a low capacity memory, (a) restart of the JPEG file Identifying a marker; (b) partitioning the jpeg file based on the identified restart marker; And (c) synthesizing the raw images decoded by the camera control processor.

According to the present invention, the method may further include comparing the size of the jpeg file with the memory size of the camera control processor prior to the step (a).

The method may further include comparing a memory size of the camera control processor with a size according to the resolution set for the JPEG file prior to step (a).

Preferably, the restart marker is generated for each preset basic pixel line during encoding, and the step (b) may divide the JPEG file for each basic pixel line.

In addition, in the step (b), it is preferable to divide the jpeg file into a predetermined number of restart marker units.

Preferably, the raw image may be an RGB565 image.

On the other hand, the basic pixel line is preferably at least one of 8, 16 and 32 lines.

According to another aspect of the present invention, there is provided a computer readable recording medium having recorded thereon a program for performing the above method.

According to another aspect of the invention, a camera control processor for decoding a jpeg file into a raw image, the camera control processor comprising a low capacity CCP memory; A decoding control processor for dividing the JPEG file based on identifying a restart marker of the JPEG file and synthesizing a plurality of raw images decoded by the camera control processor; A system memory for storing the jpeg file and the raw image; And a controller configured to control the file division and the image synthesis of the stored raw image.

According to another aspect of the present invention, a decoding control processor coupled to a camera control processor for decoding a JPEG file, comprising: a restart marker identification unit for identifying a restart marker of the JPEG file; A file divider dividing the jpeg file based on the identified restart marker; And an image synthesizer configured to synthesize a plurality of row images decoded by the camera control processor.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of an image processing apparatus, a processor and a control method thereof for split decoding a JPEG file according to the present invention.

The present invention is a method for controlling the partitioned decoding of a high capacity / high resolution jpeg file efficiently in a camera control processor having a low memory, which may be performed in software by a predetermined decoding control application, but is not limited thereto. It may be performed in hardware on a chip (processor) in which a module for control is mounted.

In addition, the division decoding process proposed in the present invention may be implemented in various forms, and it will be apparent to those skilled in the art that simple modifications of the embodiments fall within the scope of the present invention.

1 is a block diagram illustrating an interior of an image processing apparatus according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the image processing apparatus according to the present invention includes a CPU 100, a system memory 102, a decoding control processor 104, a camera control processor (CCP) 106, and a display unit ( 108).

Each component is connected via a data bus, and the CPU 100 outputs a control signal to control each component.

The system memory 102 stores an image file captured by an application required for driving an image processing apparatus and an image sensor (not shown).

According to the present invention, the system memory 102 may store a jpeg file downloaded from an external computer.

When the user requests the display of one of the jpeg files stored in the system memory 102, the jpeg file is decoded. According to a preferred embodiment of the present invention, the decoding control processor 104 causes the jpeg file to be decoded. Is divided into a plurality of files, and a process of synthesizing a plurality of raw images decoded by the CCP 106 is performed.

FIG. 2 is a block diagram of a decoding control processor according to the present invention. As shown in FIG. 2, the decoding control processor according to the present invention includes a size comparison unit 200, a restart marker identification unit 202, and a file division unit. 204 and an image synthesizer 206.

As described above, the camera control processor requires a CCP memory larger than the size of the JPEG file in order to perform decoding, otherwise decoding of the JPEG file is impossible.

Therefore, the size comparison unit 200 according to the present invention compares the size of the JPEG file stored in the system memory 102 with the CCP memory size.

The size comparison may be performed using the size information included in the header information of the jpeg file stored in the system memory 102.

When the size of the JPEG file exceeds the CCP memory size, division of the JPEG file is required.

According to the present invention, the division of the JPEG file may be performed based on the restart marker, the restart marker identification unit 202 identifies the restart marker in the JPEG file, and the file division unit 204 The effect file is divided into restart marker units of a predetermined number.

Jpef files include Start Of Image (SOI), JFIF Marker, Define Quantization Tables (DQT), Start Of Frame (SOF), Define Huffman Tables (DHT), Start Of Scan (SOS), Scan Data, and End Of Image It consists of several blocks, like).

Here, each block is divided by a marker, and various markers are used in the JPEG file structure, and a double restart marker is a marker existing in the scan data, and restores the damaged JPEG file to the maximum. It is a marker used to do this.

The process of encoding a raw image into a JPEG can be accomplished by sampling, DCT transform, quantization and Huffman coding, which is performed with data converted from RGB to Y, Cb and Cr. Here, the Y component is luminance information, and the Cb and Cr components are chroma information.

In encoding such YUV data, in general, one pixel includes all Y, Cb, and Cr components, or Y may be sampled so that each pixel includes Cb and Cr, one in two pixels. The sampling period is 1: 1: 1 and the latter sampling period is 2: 1: 1.

The sampled YUV data is expressed as a sum of cosine functions through a discrete cosine transform (DCT) process. For this purpose, the sampled data must be divided into basic blocks of a predetermined size. In this case, the 8x8 block becomes the basic block, and in the case of 2: 1: 1, the 16x16 block becomes the basic block for the DCT.

When the 8x8 block is the basic block, 8 lines, and when the 16x16 block is the basic block, 16 lines are referred to as a 'basic pixel line'.

The DCT process is sequentially performed on a basic pixel line basis. In this case, the J-CODEC generates a restart marker for each basic pixel line to be encoded.

Therefore, when the DCT process is completed and finally the JPEG file is generated through quantization and Huffman coding, as shown in FIG. 4, the base block of the DCT process is 8x8 blocks in the file compressed with the JPEG. A restart marker is included every 8 lines in the vertical direction of the pixel, and the capacity of the image data is reduced after the compression process is completed.

However, when the basic block is a 16x16 block, a restart marker may be included in every 16 lines, and the restart marker may be included in every 24 or 32 lines according to the basic block of the DCT process without being limited thereto.

Here, the quantization process is a process of removing unnecessary components from the sum components of the cosine generated in the DCT process, and the Huffman coding process is a process of converting quantized data into Huffman codes using a frequency and a type.

As such, since a restart marker is included for each basic pixel line in the encoding process to a JPEG, a single JPEG file may include a plurality of restart markers.

According to the present invention, the file dividing unit 204 may divide the JPEG file in units including a preset number of restart markers.

For example, when the basic pixel line is 8 lines and it is set to divide the JPEG file by one restart marker, the JPEG file may be divided by 8 lines.

For example, if there is a 500K byte JPEG file with VGA resolution, a camera control processor with a typical 128K or 256K byte CCP memory cannot decode the corresponding JPEG file, but splits every 8 lines as shown above. In this case, the jpeg file is divided into sixty (width divided by 480 by eight lines), and thus each split file has a size of about 9K bytes (500/60).

On the other hand, when decoding a JPEG file partitioned at 640x8 resolution into a low image, the CCP memory requires a storage space of the low image. When the low image is RGB565, 16 bits of RGB information are included per pixel. The raw image is approximately 10K bytes (640x8x16bit / 8/1000).

Therefore, according to the present invention, when a 500K byte jpeg file is divided and decoded, it is about 19K bytes per unit split file, so that the file can be decoded by a camera control processor having a low capacity CCP memory.

3A is a diagram illustrating a map structure of a CCP memory according to the present invention, in which a divided jpeg file and a decoded row image are stored in the CCP memory according to the present invention.

The camera control processor decodes and outputs the sequentially divided jpeg file. The row images are accumulated and stored in the system memory 102. The image synthesizing unit 206 according to the present invention synthesizes a plurality of row images into one. Perform the process.

FIG. 4A illustrates a result of accumulating row images when divided into eight lines. As shown in FIG. 4A, the image combining unit 206 synthesizes a plurality of row images, and the user displays a high-capacity image through the display 108. You can check the effect file.

In the above description, the decoding control processor compares the size of the JPEG file with the size of the CCP memory to control decoding. However, the decoding control processor according to the present invention does not have the size of the JPEG file itself but the resolution set for the JPEG file. The partitioning of the JPEG file may be performed by comparing the size according to the size and the CCP memory size.

As described above, a portable device including a general camera control processor can decode a low image of 400x320 resolution. If the jpeg file of 640x480 resolution is downloaded from a computer, the CCP memory of the camera control processor is low. Decoding may not be possible even if the low JPEG file itself is not larger than the CCP memory.

For example, if the resolution of the JPEG file is set to 640x480 and the raw image is in RGB565 format, the CCP memory requires at least 640x480x16 / 8/1000 = 600K bytes for low image storage, but the low-capacity CCP memory Is 128 to 256K bytes, the JPEG file of such a resolution may be impossible to decode.

Therefore, the size comparison unit 200 according to the present invention compares the size according to the resolution set for the JPEG file and the CCP memory size and identifies the restart marker when the size according to the resolution exceeds the CCP memory size. A process of dividing a file and synthesizing a raw image obtained by decoding the divided file may be performed.

In this case, the file is divided into eight lines, but as described above, the JPEG file may be divided into twelve restart marker units, that is, 96 lines.

According to the present invention, a low-capacity CCP memory may be divided by dividing a jpeg file in consideration of the size according to the size of the jpeg file or the resolution set for the jpeg file and the CCP memory size, and synthesizing the raw image from which the divided file is decoded. Even if used, the JPEG file can be decoded and the CCP memory can be efficiently used.

Although the above process has been described in the decoding control processor, the process of comparing the size of the JPEG file, restart marker identification, file segmentation, and synthesizing a plurality of row images decoded by the camera control processor may be performed through the decoding control application. will be.

5 is a diagram illustrating a split decoding process according to an embodiment of the present invention, and FIG. 5 illustrates a process of dividing a JPEG file by comparing the size of the JPEG file.

Referring to FIG. 5, the decoding control processor receives header information of a JPEG file from the system memory 102 (S500), and performs a process of comparing the size of the received JPEG file with the CCP memory size (S502). .

If the size of the JPEG file exceeds the CCP memory size, the decoding control processor identifies the restart marker (S504).

Thereafter, the file is divided into units of a predetermined number of restart markers (S506).

Thereafter, the divided jpeg file is decoded as a row image by the camera control processor (S508), and a plurality of row images corresponding to one jpeg file are stored in the system memory 102, and the decoding control processor synthesizes the same. Perform the process (S510).

Meanwhile, according to the present invention, in step S506, the file division unit may be determined within a range in which the size of the divided JPEG file and its row image size do not deviate from the CCP memory size.

6 is a diagram illustrating a split decoding process according to another embodiment of the present invention.

FIG. 6 illustrates partitioning a JPEG file by comparing a size according to a resolution set for a JPEG file. Referring to FIG. 6, a decoding control processor receives header information of a JPEG file from system memory 102 ( S600) and compares the size according to the resolution set for the JPEG file with the CCP memory size (S602).

If the size according to the resolution exceeds the CCP memory size, the decoding control processor identifies the restart marker (S604), and divides the file in units of a predetermined number of restart markers (S606).

In the file division process, the JPEG file size of the divided file and its row image size may be considered together.

The decoding of the jpeg file divided by the camera control processor is performed (S608), and the decoding control processor performs a process of synthesizing a plurality of raw images (S610).

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, according to the present invention, there is an advantage in that a device having a low capacity CCP memory can efficiently decode a high capacity JPEG file.

In addition, according to the present invention, there is an advantage in that a high resolution JPEG file can be decoded in a low resolution portable device.

In addition, according to the present invention, it is possible to increase the CCP memory efficiency and increase the processing speed by dividing the JPEG file.

Claims (14)

A method of controlling the decoding of a JPEG file using a camera control processor having a low memory, (a) identifying a restart marker of the jpeg file; (b) partitioning the jpeg file based on the identified restart marker; And (c) synthesizing the raw images decoded by the camera control processor. The method of claim 1, And comparing the size of the jpeg file with the memory size of the camera control processor prior to step (a). The method of claim 1, And comparing the memory size of the camera control processor with a size according to the resolution set for the JPEG file prior to the step (a). The method of claim 1, The restart marker is generated for each preset basic pixel line during encoding, and the step (b) divides the JPEG file for each basic pixel line. The method of claim 1, In the step (b), the decoding control method divides the jpeg file into a predetermined number of restart marker units. Claim 6 was abandoned when the registration fee was paid. The method of claim 1, And the raw image is an RGB565 image. Claim 7 was abandoned upon payment of a set-up fee. The method of claim 4, wherein And the basic pixel line is at least one of 8, 16, and 32 lines. Claim 8 was abandoned when the registration fee was paid. A computer-readable recording medium having recorded thereon a program for performing the method according to any one of claims 1 to 7. A camera control processor for decoding the jpeg file into a low image, the camera control processor including a low capacity CCP memory; A decoding control processor for dividing the JPEG file based on identifying a restart marker of the JPEG file and synthesizing a plurality of raw images decoded by the camera control processor; A system memory for storing the jpeg file and the raw image; And And a controller for controlling the file division and image synthesis of the stored raw images. Claim 10 was abandoned upon payment of a setup registration fee. The method of claim 9, And the decoding control processor performs the file division by comparing the size of the JPEG file with the memory size of the camera control processor. Claim 11 was abandoned upon payment of a setup registration fee. The method of claim 9, And the decoding control processor performs the file division by comparing a size according to a resolution set for the JPEG file with a memory size of the camera control processor. A decoding control processor coupled to a camera control processor for decoding a jpeg file, A restart marker identification unit identifying a restart marker of the jpeg file; A file divider dividing the jpeg file based on the identified restart marker; And And an image synthesizer configured to synthesize a plurality of raw images decoded by the camera control processor. The method of claim 12, And a size comparison unit comparing the size of the JPEG file with a memory size of the camera control processor. The method of claim 12, And a size comparison unit comparing a size according to the resolution set for the JPEG file with a memory size of the camera control processor.

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