pillow-avif-plugin quick hack to output 10bit HDR10PQ AVIF

how to build and install on Windows

• install miniforge
• install VS2019
• install git for windows
• install TortoiseGit
• install MSYS2 and add C:\MSYS\usr\bin to PATH environment variable
• download https://www.nasm.us/pub/nasm/releasebuilds/2.15.05/win64/nasm-2.15.05-win64.zip , unzip onto C:\apps\NASM and add D:\apps\NASM to PATH environment variable.
• on Administrator miniforge prompt, pip install meson
• build and install quick hack pillow to support R16G16B16 https://github.com/manoreken2/Pillow-R16G16B16/tree/main/winbuild
• on Administrator miniforge prompt, cd to this directory, cd winbuild and python build_prepare.py
• cd winbuild/build and build_dep_all.cmd and build_pillow_avif_plugin.cmd
• cd to this directory and python -m pip install -e .
• pip list should show pillow-avif-plugin
• to create whl, build\build_pillow_avif_plugin.cmd bdist_wheel

how to write HDR10PQ 10bit AVIF file

from PIL import Image
from pillow_avif import AvifImagePlugin
from pillow_avif import _avif
import cv2

# read R16G16B16 png file
imCV = cv2.imread("a.png", cv2.IMREAD_UNCHANGED)
imCV = cv2.cvtColor(imCV, cv2.COLOR_BGR2RGB)

print("imCV {0} {1}".format(imCV.dtype, imCV.shape))

im = Image.fromarray(imCV, mode="R16G16B16")
im.save("out.avif", quality=100, range="full", subsampling="4:4:4", depth=10, color_primaries=9, transfer_characteristics=16, matrix_coefficients=0)

encoding options

"qmin"

encoding quality. integer. Quality range is 0 to 63

encoder->minQuantizer

value	meanings
0	AVIF_QUANTIZER_BEST_QUALITY
63	AVIF_QUANTIZER_WORST_QUALITY

"qmax"

encoding quality. integer. Quality range is 0 to 63

encoder->maxQuantizer

value	meanings
0	AVIF_QUANTIZER_BEST_QUALITY
63	AVIF_QUANTIZER_WORST_QUALITY

"speed"

encoding speed. slower should make for a better quality. integer.

value	meanings
-1	AVIF_SPEED_DEFAULT
0	AVIF_SPEED_SLOWEST
10	AVIF_SPEED_FASTEST

"codec"

default is "auto". encoder availability depends on the build settings of libav1f.

value	meanings
"auto"	auto
"dav1d"	dav1d
"libgav1"	libgav1
"aom"	aom
"rav1e"	rav1e
"svt"	svt

"range"

value	meanings
"full"	full quantization range image. ex. ST 2084 PQ requires it
"limited"	limited quantization range image.

"subsampling"

value	meanings
"4:4:4"	YCbCr 4:4:4 or lossless GBR encoding
"4:2:2"	YCbCr422
"4:2:0"	YCbCr420
"4:0:0"	YCbCr400

"depth"

color bitdepth. 8, 10 or 12

"quality"

encoding quality, integer number ranging 0 to 100

value	meanings
0	worst color encoding quality
75	default color encoding quality
100	best color encoding quality

"tile_rows_log2"

default is 0

"tile_cols_log2"

default is 0

"alpha_premultiplied"

if true, enc_options.alpha_premultiplied is AVIF_TRUE

"autotiling"

if true, enc_options.autotiling is AVIF_TRUE

"icc_bytes"

it is set to avifImageSetProfileICC()

"exif_bytes"

is is set to avifImageSetMetadataExif()

"xmp_bytes"

is is set to avifImageSetMetadataXMP

"advanced"

follows pytuple. it is set to avifEncoderSetCodecSpecificOption()

"color_primaries"

value	meanings
1	BT.709, Rec.709 or sRGB
2	Unspecified
9	BT.2020, Rec.2020 or Rec.2100
12	DCI P3 or SMPTE EG 432-1

"transfer_characteristics"

value	meanings
1	BT.709 or Rec.709
2	Unspecified
6	BT.601
8	Linear
13	sRGB
14	BT.2020 10bit
15	BT.2020 12bit
16	ST 2084 PQ for Rec.2020
18	HLG

"matrix_coefficients"

value	meanings
0	Identity matrix for lossless encoding. Stores color as GBR
1	BT.709 YCbCr
2	Unspecified
6	BT.601 YCbCr (default for lossy encodings)
8	YCgCo
9	BT.2020 non-constant luminance, BT.2100 YCbCr
10	BT.2020 constant luminance
11	SMPTE ST 2085 YDzDx
14	BT.2100 ICtCp