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Cosmetics

This commit is contained in:
Dominic Szablewski 2021-12-11 12:54:01 +01:00
parent 0ad304d761
commit c2edcd3d7a
1 changed files with 12 additions and 11 deletions
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23
qoi.h
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@ -123,22 +123,22 @@ The byte stream is padded with 8 zero-bytes at the end.
The possible chunks are: The possible chunks are:
- QOI_OP_INDEX ---------- .- QOI_OP_INDEX ----------.
| Byte[0] | | Byte[0] |
| 7 6 5 4 3 2 1 0 | | 7 6 5 4 3 2 1 0 |
|-------+-----------------| |-------+-----------------|
| 0 0 | index | | 0 0 | index |
`-------------------------`
2-bit tag b00 2-bit tag b00
6-bit index into the color index array: 0..63 6-bit index into the color index array: 0..63
- QOI_OP_DIFF ----------- .- QOI_OP_DIFF -----------.
| Byte[0] | | Byte[0] |
| 7 6 5 4 3 2 1 0 | | 7 6 5 4 3 2 1 0 |
|-------+-----+-----+-----| |-------+-----+-----+-----|
| 0 1 | dr | dg | db | | 0 1 | dr | dg | db |
`-------------------------`
2-bit tag b01 2-bit tag b01
2-bit red channel difference from the previous pixel between -2..1 2-bit red channel difference from the previous pixel between -2..1
2-bit green channel difference from the previous pixel between -2..1 2-bit green channel difference from the previous pixel between -2..1
@ -151,11 +151,12 @@ Values are stored as unsigned integers with a bias of 2. E.g. -2 is stored as
0 (b00). 1 is stored as 3 (b11). 0 (b00). 1 is stored as 3 (b11).
.- QOI_OP_LUMA -------------------------------------.
| Byte[0] | Byte[1] | | Byte[0] | Byte[1] |
| 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 | | 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |
|-------+-----------------+-------------+-----------| |-------+-----------------+-------------+-----------|
| 1 0 | green diff | dr - dg | db - dg | | 1 0 | green diff | dr - dg | db - dg |
`---------------------------------------------------`
2-bit tag b10 2-bit tag b10
6-bit green channel difference from the previous pixel -32..31 6-bit green channel difference from the previous pixel -32..31
4-bit red channel difference minus green channel difference -8..7 4-bit red channel difference minus green channel difference -8..7
@ -174,12 +175,12 @@ Values are stored as unsigned integers with a bias of 32 for the green channel
and a bias of 8 for the red and blue channel. and a bias of 8 for the red and blue channel.
- QOI_OP_RUN ------------ .- QOI_OP_RUN ------------.
| Byte[0] | | Byte[0] |
| 7 6 5 4 3 2 1 0 | | 7 6 5 4 3 2 1 0 |
|-------+-----------------| |-------+-----------------|
| 1 1 | run | | 1 1 | run |
`-------------------------`
2-bit tag b11 2-bit tag b11
6-bit run-length repeating the previous pixel: 1..62 6-bit run-length repeating the previous pixel: 1..62
@ -188,24 +189,24 @@ The run-length is stored with a bias of 1. Note that the run-lengths 63 and 64
QOI_OP_RGBA tags. QOI_OP_RGBA tags.
- QOI_OP_RGB ------------------------------------------ .- QOI_OP_RGB ------------------------------------------.
| Byte[0] | Byte[1] | Byte[2] | Byte[3] | | Byte[0] | Byte[1] | Byte[2] | Byte[3] |
| 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 | | 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 |
|-------------------------+---------+---------+---------| |-------------------------+---------+---------+---------|
| 1 1 1 1 1 1 1 0 | red | green | blue | | 1 1 1 1 1 1 1 0 | red | green | blue |
`-------------------------------------------------------`
8-bit tag b11111110 8-bit tag b11111110
8-bit red channel value 8-bit red channel value
8-bit green channel value 8-bit green channel value
8-bit blue channel value 8-bit blue channel value
- QOI_OP_RGBA ---------------------------------------------------- .- QOI_OP_RGBA ---------------------------------------------------.
| Byte[0] | Byte[1] | Byte[2] | Byte[3] | Byte[4] | | Byte[0] | Byte[1] | Byte[2] | Byte[3] | Byte[4] |
| 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 | | 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 |
|-------------------------+---------+---------+---------+---------| |-------------------------+---------+---------+---------+---------|
| 1 1 1 1 1 1 1 1 | red | green | blue | alpha | | 1 1 1 1 1 1 1 1 | red | green | blue | alpha |
`-----------------------------------------------------------------`
8-bit tag b11111111 8-bit tag b11111111
8-bit red channel value 8-bit red channel value
8-bit green channel value 8-bit green channel value