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Doc: Further clarify MCU definition

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DRC
2024-09-01 11:23:31 -04:00
parent 7ec70ee891
commit 797c6ccd98
7 changed files with 60 additions and 42 deletions
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22
turbojpeg.h
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@@ -201,10 +201,13 @@ enum TJSAMP {
* In a typical lossy JPEG image, 8x8 blocks of DCT coefficients for each
* component are interleaved in a single scan. If the image uses chrominance
* subsampling, then multiple luminance blocks are stored together, followed by
* a single block for each chrominance component. The combination of the
* full-resolution luminance block(s) and the (possibly subsampled) chrominance
* blocks corresponding to the same pixels is called a "Minimum Coded Unit"
* (MCU.) In a non-interleaved lossy JPEG image, each component is stored in a
* a single block for each chrominance component. The minimum set of
* full-resolution luminance block(s) and corresponding (possibly subsampled)
* chrominance blocks necessary to represent at least one DCT block per
* component is called a "Minimum Coded Unit" or "MCU". (For example, an MCU
* in an interleaved lossy JPEG image that uses 4:2:2 subsampling consists of
* two luminance blocks followed by one block for each chrominance component.)
* In a non-interleaved lossy JPEG image, each component is stored in a
* separate scan, and an MCU is a single DCT block, so we use the term "iMCU"
* (interleaved MCU) to refer to the equivalent of an MCU in an interleaved
* JPEG image. For the common case of interleaved JPEG images, an iMCU is the
@@ -226,10 +229,13 @@ static const int tjMCUWidth[TJ_NUMSAMP] = { 8, 16, 16, 8, 8, 32, 8 };
* In a typical lossy JPEG image, 8x8 blocks of DCT coefficients for each
* component are interleaved in a single scan. If the image uses chrominance
* subsampling, then multiple luminance blocks are stored together, followed by
* a single block for each chrominance component. The combination of the
* full-resolution luminance block(s) and the (possibly subsampled) chrominance
* blocks corresponding to the same pixels is called a "Minimum Coded Unit"
* (MCU.) In a non-interleaved lossy JPEG image, each component is stored in a
* a single block for each chrominance component. The minimum set of
* full-resolution luminance block(s) and corresponding (possibly subsampled)
* chrominance blocks necessary to represent at least one DCT block per
* component is called a "Minimum Coded Unit" or "MCU". (For example, an MCU
* in an interleaved lossy JPEG image that uses 4:2:2 subsampling consists of
* two luminance blocks followed by one block for each chrominance component.)
* In a non-interleaved lossy JPEG image, each component is stored in a
* separate scan, and an MCU is a single DCT block, so we use the term "iMCU"
* (interleaved MCU) to refer to the equivalent of an MCU in an interleaved
* JPEG image. For the common case of interleaved JPEG images, an iMCU is the