:orphan:
.. _PNG-PIL:
PNG-PIL Portable network graphics
=================================
Extensions: ``.png``
A PNG format based on Pillow.
This format supports grayscale, RGB and RGBA images.
Parameters for reading
----------------------
ignoregamma : bool
Avoid gamma correction. Default True.
pilmode : str
From the Pillow documentation:
* 'L' (8-bit pixels, grayscale)
* 'P' (8-bit pixels, mapped to any other mode using a color palette)
* 'RGB' (3x8-bit pixels, true color)
* 'RGBA' (4x8-bit pixels, true color with transparency mask)
* 'CMYK' (4x8-bit pixels, color separation)
* 'YCbCr' (3x8-bit pixels, color video format)
* 'I' (32-bit signed integer pixels)
* 'F' (32-bit floating point pixels)
PIL also provides limited support for a few special modes, including
'LA' ('L' with alpha), 'RGBX' (true color with padding) and 'RGBa'
(true color with premultiplied alpha).
When translating a color image to grayscale (mode 'L', 'I' or 'F'),
the library uses the ITU-R 601-2 luma transform::
L = R * 299/1000 + G * 587/1000 + B * 114/1000
as_gray : bool
If True, the image is converted using mode 'F'. When `mode` is
not None and `as_gray` is True, the image is first converted
according to `mode`, and the result is then "flattened" using
mode 'F'.
Parameters for saving
---------------------
optimize : bool
If present and true, instructs the PNG writer to make the output file
as small as possible. This includes extra processing in order to find
optimal encoder settings.
transparency:
This option controls what color image to mark as transparent.
dpi: tuple of two scalars
The desired dpi in each direction.
pnginfo: PIL.PngImagePlugin.PngInfo
Object containing text tags.
compress_level: int
ZLIB compression level, a number between 0 and 9: 1 gives best speed,
9 gives best compression, 0 gives no compression at all. Default is 9.
When ``optimize`` option is True ``compress_level`` has no effect
(it is set to 9 regardless of a value passed).
compression: int
Compatibility with the freeimage PNG format. If given, it overrides
compress_level.
icc_profile:
The ICC Profile to include in the saved file.
bits (experimental): int
This option controls how many bits to store. If omitted,
the PNG writer uses 8 bits (256 colors).
quantize:
Compatibility with the freeimage PNG format. If given, it overrides
bits. In this case, given as a number between 1-256.
dictionary (experimental): dict
Set the ZLIB encoder dictionary.
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