andrews05
bbde68ddce
Refactor optimize_raw ( #670 )
...
Code always tends to get messy over time. I've found the `optimize_raw`
function increasingly harder to read, particularly after the addition of
fast mode, so I've taken some time to refactor and simplify it.
One change of note here is the main compression trials now use the
Evaluator. This means verbose output is a little different which is
shown below.
There is no change to performance or output size.
`-vvo2`: master
```
Processing: tests/files/rgba_8_should_be_palette_4.png
500x400 pixels, PNG format
8-bit RGB + Alpha, non-interlaced
IDAT size = 2757 bytes
File size = 18109 bytes
Eval: 4-bit Indexed (5 colors) None 1837 bytes
Eval: 8-bit Indexed (5 colors) None 1988 bytes
Eval: 4-bit Indexed (5 colors) Bigrams >1837 bytes
Eval: 8-bit Indexed (5 colors) Bigrams >1837 bytes
Transformed image to 4-bit Indexed (5 colors), non-interlaced
Evaluating: 2 filters
Eval: 4-bit Indexed (5 colors) Sub >1810 bytes
Eval: 4-bit Indexed (5 colors) Entropy >1810 bytes
Trying: None
zc = 11 f = None 1583 bytes
Found better combination:
zc = 11 f = None 1583 bytes
IDAT size = 1583 bytes (1174 bytes decrease)
file size = 16962 bytes (1147 bytes = 6.33% decrease)
16962 bytes (6.33% smaller): Running in pretend mode, no output
```
`-vvo2`: PR
```
Processing: tests/files/rgba_8_should_be_palette_4.png
500x400 pixels, PNG format
8-bit RGB + Alpha, non-interlaced
IDAT size = 2757 bytes
File size = 18109 bytes
Eval: 4-bit Indexed (5 colors) None 1837 bytes
Eval: 8-bit Indexed (5 colors) None 1988 bytes
Eval: 4-bit Indexed (5 colors) Bigrams >1837 bytes
Eval: 8-bit Indexed (5 colors) Bigrams >1837 bytes
Transformed image to 4-bit Indexed (5 colors), non-interlaced
Evaluating 2 filters
Eval: 4-bit Indexed (5 colors) Sub >1810 bytes
Eval: 4-bit Indexed (5 colors) Entropy >1810 bytes
Trying filter None with zc = 11
1610 bytes
Found better result:
zc = 11, f = None
IDAT size = 1583 bytes (1174 bytes decrease)
file size = 16962 bytes (1147 bytes = 6.33% decrease)
16962 bytes (6.33% smaller): Running in pretend mode, no output
```
`-vvZo5`: master
```
Processing: tests/files/rgba_8_should_be_palette_4.png
500x400 pixels, PNG format
8-bit RGB + Alpha, non-interlaced
IDAT size = 2757 bytes
File size = 18109 bytes
Eval: 8-bit Indexed (battiato sort) None 1821 bytes
Eval: 4-bit Indexed (5 colors) None 1657 bytes
Eval: 8-bit Indexed (mzeng sort) None 1821 bytes
Eval: 8-bit Indexed (5 colors) None 1821 bytes
Eval: 8-bit Indexed (battiato sort) Bigrams >1821 bytes
Eval: 4-bit Indexed (5 colors) Bigrams >1657 bytes
Eval: 8-bit Indexed (mzeng sort) Bigrams >1657 bytes
Eval: 8-bit Indexed (5 colors) Bigrams >1657 bytes
Transformed image to 4-bit Indexed (5 colors), non-interlaced
Trying: 8 filters
zc = zopfli f = Brute 1562 bytes
zc = zopfli f = Sub >1562 bytes
zc = zopfli f = Bigrams >1562 bytes
zc = zopfli f = None 1407 bytes
zc = zopfli f = Up >1407 bytes
zc = zopfli f = MinSum >1407 bytes
zc = zopfli f = BigEnt >1407 bytes
zc = zopfli f = Entropy >1407 bytes
Found better combination:
zc = zopfli f = None 1407 bytes
IDAT size = 1407 bytes (1350 bytes decrease)
file size = 16786 bytes (1323 bytes = 7.31% decrease)
16786 bytes (7.31% smaller): Running in pretend mode, no output
```
`-vvZo5`: PR
```
Processing: tests/files/rgba_8_should_be_palette_4.png
500x400 pixels, PNG format
8-bit RGB + Alpha, non-interlaced
IDAT size = 2757 bytes
File size = 18109 bytes
Eval: 8-bit Indexed (battiato sort) None 1821 bytes
Eval: 4-bit Indexed (5 colors) None 1657 bytes
Eval: 8-bit Indexed (mzeng sort) None 1821 bytes
Eval: 8-bit Indexed (5 colors) None 1821 bytes
Eval: 8-bit Indexed (battiato sort) Bigrams >1657 bytes
Eval: 4-bit Indexed (5 colors) Bigrams >1657 bytes
Eval: 8-bit Indexed (mzeng sort) Bigrams >1657 bytes
Eval: 8-bit Indexed (5 colors) Bigrams >1657 bytes
Transformed image to 4-bit Indexed (5 colors), non-interlaced
Trying 8 filters with zopfli, zi = 15
Eval: 4-bit Indexed (5 colors) Brute 1589 bytes
Eval: 4-bit Indexed (5 colors) Bigrams 1641 bytes
Eval: 4-bit Indexed (5 colors) Sub 1711 bytes
Eval: 4-bit Indexed (5 colors) None 1434 bytes
Eval: 4-bit Indexed (5 colors) Up 1764 bytes
Eval: 4-bit Indexed (5 colors) MinSum 1760 bytes
Eval: 4-bit Indexed (5 colors) BigEnt 1742 bytes
Eval: 4-bit Indexed (5 colors) Entropy 1748 bytes
Found better result:
zopfli, zi = 15, f = None
IDAT size = 1407 bytes (1350 bytes decrease)
file size = 16786 bytes (1323 bytes = 7.31% decrease)
16786 bytes (7.31% smaller): Running in pretend mode, no output
```
2025-01-29 20:53:11 +01:00
