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| author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
|---|---|---|
| committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
| commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
| tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/PIL/JpegPresets.py | |
| parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
| download | gn-ai-master.tar.gz | |
Diffstat (limited to '.venv/lib/python3.12/site-packages/PIL/JpegPresets.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/PIL/JpegPresets.py | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/PIL/JpegPresets.py b/.venv/lib/python3.12/site-packages/PIL/JpegPresets.py new file mode 100644 index 00000000..d0e64a35 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/PIL/JpegPresets.py @@ -0,0 +1,242 @@ +""" +JPEG quality settings equivalent to the Photoshop settings. +Can be used when saving JPEG files. + +The following presets are available by default: +``web_low``, ``web_medium``, ``web_high``, ``web_very_high``, ``web_maximum``, +``low``, ``medium``, ``high``, ``maximum``. +More presets can be added to the :py:data:`presets` dict if needed. + +To apply the preset, specify:: + + quality="preset_name" + +To apply only the quantization table:: + + qtables="preset_name" + +To apply only the subsampling setting:: + + subsampling="preset_name" + +Example:: + + im.save("image_name.jpg", quality="web_high") + +Subsampling +----------- + +Subsampling is the practice of encoding images by implementing less resolution +for chroma information than for luma information. +(ref.: https://en.wikipedia.org/wiki/Chroma_subsampling) + +Possible subsampling values are 0, 1 and 2 that correspond to 4:4:4, 4:2:2 and +4:2:0. + +You can get the subsampling of a JPEG with the +:func:`.JpegImagePlugin.get_sampling` function. + +In JPEG compressed data a JPEG marker is used instead of an EXIF tag. +(ref.: https://exiv2.org/tags.html) + + +Quantization tables +------------------- + +They are values use by the DCT (Discrete cosine transform) to remove +*unnecessary* information from the image (the lossy part of the compression). +(ref.: https://en.wikipedia.org/wiki/Quantization_matrix#Quantization_matrices, +https://en.wikipedia.org/wiki/JPEG#Quantization) + +You can get the quantization tables of a JPEG with:: + + im.quantization + +This will return a dict with a number of lists. You can pass this dict +directly as the qtables argument when saving a JPEG. + +The quantization table format in presets is a list with sublists. These formats +are interchangeable. + +Libjpeg ref.: +https://web.archive.org/web/20120328125543/http://www.jpegcameras.com/libjpeg/libjpeg-3.html + +""" + +from __future__ import annotations + +# fmt: off +presets = { + 'web_low': {'subsampling': 2, # "4:2:0" + 'quantization': [ + [20, 16, 25, 39, 50, 46, 62, 68, + 16, 18, 23, 38, 38, 53, 65, 68, + 25, 23, 31, 38, 53, 65, 68, 68, + 39, 38, 38, 53, 65, 68, 68, 68, + 50, 38, 53, 65, 68, 68, 68, 68, + 46, 53, 65, 68, 68, 68, 68, 68, + 62, 65, 68, 68, 68, 68, 68, 68, + 68, 68, 68, 68, 68, 68, 68, 68], + [21, 25, 32, 38, 54, 68, 68, 68, + 25, 28, 24, 38, 54, 68, 68, 68, + 32, 24, 32, 43, 66, 68, 68, 68, + 38, 38, 43, 53, 68, 68, 68, 68, + 54, 54, 66, 68, 68, 68, 68, 68, + 68, 68, 68, 68, 68, 68, 68, 68, + 68, 68, 68, 68, 68, 68, 68, 68, + 68, 68, 68, 68, 68, 68, 68, 68] + ]}, + 'web_medium': {'subsampling': 2, # "4:2:0" + 'quantization': [ + [16, 11, 11, 16, 23, 27, 31, 30, + 11, 12, 12, 15, 20, 23, 23, 30, + 11, 12, 13, 16, 23, 26, 35, 47, + 16, 15, 16, 23, 26, 37, 47, 64, + 23, 20, 23, 26, 39, 51, 64, 64, + 27, 23, 26, 37, 51, 64, 64, 64, + 31, 23, 35, 47, 64, 64, 64, 64, + 30, 30, 47, 64, 64, 64, 64, 64], + [17, 15, 17, 21, 20, 26, 38, 48, + 15, 19, 18, 17, 20, 26, 35, 43, + 17, 18, 20, 22, 26, 30, 46, 53, + 21, 17, 22, 28, 30, 39, 53, 64, + 20, 20, 26, 30, 39, 48, 64, 64, + 26, 26, 30, 39, 48, 63, 64, 64, + 38, 35, 46, 53, 64, 64, 64, 64, + 48, 43, 53, 64, 64, 64, 64, 64] + ]}, + 'web_high': {'subsampling': 0, # "4:4:4" + 'quantization': [ + [6, 4, 4, 6, 9, 11, 12, 16, + 4, 5, 5, 6, 8, 10, 12, 12, + 4, 5, 5, 6, 10, 12, 14, 19, + 6, 6, 6, 11, 12, 15, 19, 28, + 9, 8, 10, 12, 16, 20, 27, 31, + 11, 10, 12, 15, 20, 27, 31, 31, + 12, 12, 14, 19, 27, 31, 31, 31, + 16, 12, 19, 28, 31, 31, 31, 31], + [7, 7, 13, 24, 26, 31, 31, 31, + 7, 12, 16, 21, 31, 31, 31, 31, + 13, 16, 17, 31, 31, 31, 31, 31, + 24, 21, 31, 31, 31, 31, 31, 31, + 26, 31, 31, 31, 31, 31, 31, 31, + 31, 31, 31, 31, 31, 31, 31, 31, + 31, 31, 31, 31, 31, 31, 31, 31, + 31, 31, 31, 31, 31, 31, 31, 31] + ]}, + 'web_very_high': {'subsampling': 0, # "4:4:4" + 'quantization': [ + [2, 2, 2, 2, 3, 4, 5, 6, + 2, 2, 2, 2, 3, 4, 5, 6, + 2, 2, 2, 2, 4, 5, 7, 9, + 2, 2, 2, 4, 5, 7, 9, 12, + 3, 3, 4, 5, 8, 10, 12, 12, + 4, 4, 5, 7, 10, 12, 12, 12, + 5, 5, 7, 9, 12, 12, 12, 12, + 6, 6, 9, 12, 12, 12, 12, 12], + [3, 3, 5, 9, 13, 15, 15, 15, + 3, 4, 6, 11, 14, 12, 12, 12, + 5, 6, 9, 14, 12, 12, 12, 12, + 9, 11, 14, 12, 12, 12, 12, 12, + 13, 14, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12] + ]}, + 'web_maximum': {'subsampling': 0, # "4:4:4" + 'quantization': [ + [1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 2, + 1, 1, 1, 1, 1, 1, 2, 2, + 1, 1, 1, 1, 1, 2, 2, 3, + 1, 1, 1, 1, 2, 2, 3, 3, + 1, 1, 1, 2, 2, 3, 3, 3, + 1, 1, 2, 2, 3, 3, 3, 3], + [1, 1, 1, 2, 2, 3, 3, 3, + 1, 1, 1, 2, 3, 3, 3, 3, + 1, 1, 1, 3, 3, 3, 3, 3, + 2, 2, 3, 3, 3, 3, 3, 3, + 2, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3, + 3, 3, 3, 3, 3, 3, 3, 3] + ]}, + 'low': {'subsampling': 2, # "4:2:0" + 'quantization': [ + [18, 14, 14, 21, 30, 35, 34, 17, + 14, 16, 16, 19, 26, 23, 12, 12, + 14, 16, 17, 21, 23, 12, 12, 12, + 21, 19, 21, 23, 12, 12, 12, 12, + 30, 26, 23, 12, 12, 12, 12, 12, + 35, 23, 12, 12, 12, 12, 12, 12, + 34, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12], + [20, 19, 22, 27, 20, 20, 17, 17, + 19, 25, 23, 14, 14, 12, 12, 12, + 22, 23, 14, 14, 12, 12, 12, 12, + 27, 14, 14, 12, 12, 12, 12, 12, + 20, 14, 12, 12, 12, 12, 12, 12, + 20, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12] + ]}, + 'medium': {'subsampling': 2, # "4:2:0" + 'quantization': [ + [12, 8, 8, 12, 17, 21, 24, 17, + 8, 9, 9, 11, 15, 19, 12, 12, + 8, 9, 10, 12, 19, 12, 12, 12, + 12, 11, 12, 21, 12, 12, 12, 12, + 17, 15, 19, 12, 12, 12, 12, 12, + 21, 19, 12, 12, 12, 12, 12, 12, + 24, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12], + [13, 11, 13, 16, 20, 20, 17, 17, + 11, 14, 14, 14, 14, 12, 12, 12, + 13, 14, 14, 14, 12, 12, 12, 12, + 16, 14, 14, 12, 12, 12, 12, 12, + 20, 14, 12, 12, 12, 12, 12, 12, + 20, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12] + ]}, + 'high': {'subsampling': 0, # "4:4:4" + 'quantization': [ + [6, 4, 4, 6, 9, 11, 12, 16, + 4, 5, 5, 6, 8, 10, 12, 12, + 4, 5, 5, 6, 10, 12, 12, 12, + 6, 6, 6, 11, 12, 12, 12, 12, + 9, 8, 10, 12, 12, 12, 12, 12, + 11, 10, 12, 12, 12, 12, 12, 12, + 12, 12, 12, 12, 12, 12, 12, 12, + 16, 12, 12, 12, 12, 12, 12, 12], + [7, 7, 13, 24, 20, 20, 17, 17, + 7, 12, 16, 14, 14, 12, 12, 12, + 13, 16, 14, 14, 12, 12, 12, 12, + 24, 14, 14, 12, 12, 12, 12, 12, + 20, 14, 12, 12, 12, 12, 12, 12, + 20, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12, + 17, 12, 12, 12, 12, 12, 12, 12] + ]}, + 'maximum': {'subsampling': 0, # "4:4:4" + 'quantization': [ + [2, 2, 2, 2, 3, 4, 5, 6, + 2, 2, 2, 2, 3, 4, 5, 6, + 2, 2, 2, 2, 4, 5, 7, 9, + 2, 2, 2, 4, 5, 7, 9, 12, + 3, 3, 4, 5, 8, 10, 12, 12, + 4, 4, 5, 7, 10, 12, 12, 12, + 5, 5, 7, 9, 12, 12, 12, 12, + 6, 6, 9, 12, 12, 12, 12, 12], + [3, 3, 5, 9, 13, 15, 15, 15, + 3, 4, 6, 10, 14, 12, 12, 12, + 5, 6, 9, 14, 12, 12, 12, 12, + 9, 10, 14, 12, 12, 12, 12, 12, + 13, 14, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12, + 15, 12, 12, 12, 12, 12, 12, 12] + ]}, +} +# fmt: on |