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Pillow/src/PIL/JpegPresets.py

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Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
"""
JPEG quality settings equivalent to the Photoshop settings.
promote JpegPresets from autodoc section
2020-06-14 14:46:52 +03:00
Can be used when saving JPEG files.
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
promote JpegPresets from autodoc section
2020-06-14 14:46:52 +03:00
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.
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
To apply the preset, specify::
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
quality="preset_name"
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
To apply only the quantization table::
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
qtables="preset_name"
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
To apply only the subsampling setting::
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
subsampling="preset_name"
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
Example::
im.save("image_name.jpg", quality="web_high")
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Subsampling
-----------
Subsampling is the practice of encoding images by implementing less resolution
for chroma information than for luma information.
'make linkcheck' fixes
2015-12-07 23:03:36 +03:00
(ref.: https://en.wikipedia.org/wiki/Chroma_subsampling)
Fix some docstrings
2013-04-12 23:53:17 +04:00
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Possible subsampling values are 0, 1 and 2 that correspond to 4:4:4, 4:2:2 and
Fix wrong formula for subsampling=2 while JPEG saving
2017-08-27 20:03:36 +03:00
4:2:0.
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
You can get the subsampling of a JPEG with the
fix docs typos
2020-08-11 03:12:26 +03:00
:func:`.JpegImagePlugin.get_sampling` function.
Fix mismatched name, add explanation. Mention why this information is not available in the EXIF tag specified for this purpose.
2019-10-28 09:36:33 +03:00
In JPEG compressed data a JPEG marker is used instead of an EXIF tag.
(ref.: https://www.exiv2.org/tags.html)
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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).
'make linkcheck' fixes
2015-12-07 23:03:36 +03:00
(ref.: https://en.wikipedia.org/wiki/Quantization_matrix#Quantization_matrices,
https://en.wikipedia.org/wiki/JPEG#Quantization)
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
Fix some docstrings
2013-04-12 23:53:17 +04:00
You can get the quantization tables of a JPEG with::
im.quantization
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
De-zigzag JPEG's DQT when loading; deprecate convert_dict_qtables Re-order the JPEG quantization tables to normal order when loading. This wastes a few CPU cycles if you don't need them. But it has the advantage of hiding the zigzag order JPEG implementation detail of these tables completely from Pillow users. This difference has led to cases where: * arrays in zigzag order were taken from a dict and passed directly as a qtables parameter, causing them to be "zigzagged" again by libjpeg. * dicts with lists in normal order being passed to JpegImagePlugin.convert_dict_qtables, causing them to be unnecessarily "de-zigzagged".
2020-10-17 21:20:59 +03:00
This will return a dict with a number of lists. You can pass this dict
flake8
2014-08-28 15:44:19 +04:00
directly as the qtables argument when saving a JPEG.
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
De-zigzag JPEG's DQT when loading; deprecate convert_dict_qtables Re-order the JPEG quantization tables to normal order when loading. This wastes a few CPU cycles if you don't need them. But it has the advantage of hiding the zigzag order JPEG implementation detail of these tables completely from Pillow users. This difference has led to cases where: * arrays in zigzag order were taken from a dict and passed directly as a qtables parameter, causing them to be "zigzagged" again by libjpeg. * dicts with lists in normal order being passed to JpegImagePlugin.convert_dict_qtables, causing them to be unnecessarily "de-zigzagged".
2020-10-17 21:20:59 +03:00
The quantization table format in presets is a list with sublists. These formats
are interchangeable.
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
flake8: E501 line too long
2018-10-24 22:24:03 +03:00
Libjpeg ref.:
https://web.archive.org/web/20120328125543/http://www.jpegcameras.com/libjpeg/libjpeg-3.html
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
"""
Format with Black
2019-03-21 16:28:20 +03:00
# fmt: off
Run yesqa to remove redundant noqa
2020-06-06 13:15:17 +03:00
presets = {
Fix wrong formula for subsampling=2 while JPEG saving
2017-08-27 20:03:36 +03:00
'web_low': {'subsampling': 2, # "4:2:0"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
[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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Fix wrong formula for subsampling=2 while JPEG saving
2017-08-27 20:03:36 +03:00
'web_medium': {'subsampling': 2, # "4:2:0"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
[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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Various Flake8 fixes
2015-04-24 02:26:52 +03:00
'web_high': {'subsampling': 0, # "4:4:4"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Lint fixes
2020-06-06 05:07:57 +03:00
[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,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
11, 10, 12, 15, 20, 27, 31, 31,
12, 12, 14, 19, 27, 31, 31, 31,
16, 12, 19, 28, 31, 31, 31, 31],
Lint fixes
2020-06-06 05:07:57 +03:00
[7, 7, 13, 24, 26, 31, 31, 31,
7, 12, 16, 21, 31, 31, 31, 31,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Various Flake8 fixes
2015-04-24 02:26:52 +03:00
'web_very_high': {'subsampling': 0, # "4:4:4"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Lint fixes
2020-06-06 05:07:57 +03:00
[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,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Various Flake8 fixes
2015-04-24 02:26:52 +03:00
'web_maximum': {'subsampling': 0, # "4:4:4"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
[1, 1, 1, 1, 1, 1, 1, 1,
Cleanup WS, courtesy of @Arfrever find * -type f "-(" -name "*.bdf" -o -name "*.c" -o -name "*.h" -o -name "*.py" -o -name "*.rst" -o -name "*.txt" "-)" -exec sed -e "s/[[:space:]]*$//" -i {} \;
2013-07-01 02:42:19 +04:00
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 2,
1, 1, 1, 1, 1, 1, 2, 2,
1, 1, 1, 1, 1, 2, 2, 3,
1, 1, 1, 1, 2, 2, 3, 3,
1, 1, 1, 2, 2, 3, 3, 3,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
1, 1, 2, 2, 3, 3, 3, 3],
Flake8 fixes
2015-08-25 15:27:18 +03:00
[1, 1, 1, 2, 2, 3, 3, 3,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
1, 1, 1, 2, 3, 3, 3, 3,
1, 1, 1, 3, 3, 3, 3, 3,
2, 2, 3, 3, 3, 3, 3, 3,
2, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3,
Cleanup WS, courtesy of @Arfrever find * -type f "-(" -name "*.bdf" -o -name "*.c" -o -name "*.h" -o -name "*.py" -o -name "*.rst" -o -name "*.txt" "-)" -exec sed -e "s/[[:space:]]*$//" -i {} \;
2013-07-01 02:42:19 +04:00
3, 3, 3, 3, 3, 3, 3, 3,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
3, 3, 3, 3, 3, 3, 3, 3]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Fix wrong formula for subsampling=2 while JPEG saving
2017-08-27 20:03:36 +03:00
'low': {'subsampling': 2, # "4:2:0"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
[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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Fix wrong formula for subsampling=2 while JPEG saving
2017-08-27 20:03:36 +03:00
'medium': {'subsampling': 2, # "4:2:0"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
[12, 8, 8, 12, 17, 21, 24, 17,
Lint fixes
2020-06-06 05:07:57 +03:00
8, 9, 9, 11, 15, 19, 12, 12,
8, 9, 10, 12, 19, 12, 12, 12,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Various Flake8 fixes
2015-04-24 02:26:52 +03:00
'high': {'subsampling': 0, # "4:4:4"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Lint fixes
2020-06-06 05:07:57 +03:00
[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,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
11, 10, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12,
16, 12, 12, 12, 12, 12, 12, 12],
Lint fixes
2020-06-06 05:07:57 +03:00
[7, 7, 13, 24, 20, 20, 17, 17,
7, 12, 16, 14, 14, 12, 12, 12,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
Various Flake8 fixes
2015-04-24 02:26:52 +03:00
'maximum': {'subsampling': 0, # "4:4:4"
Flake8 fixes
2015-08-25 15:27:18 +03:00
'quantization': [
Lint fixes
2020-06-06 05:07:57 +03:00
[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,
Added quantization tables and subsampling options to the JPEG encoder.
2013-03-07 05:23:02 +04:00
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]
Flake8 fixes
2015-08-25 15:27:18 +03:00
]},
flake8
2014-08-28 15:44:19 +04:00
}
Format with Black
2019-03-21 16:28:20 +03:00
# fmt: on
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