PNG Quant
The PngquantPostProcessor is a built-in post-processor that performs a number of
safe, lossy optimizations on PNG encoded images.
To add this post-processor to the filter set created in the thumbnail usage example use:
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# app/config/config.yml
liip_imagine:
filter_sets:
my_thumb:
filters:
thumbnail: { size: [120, 90], mode: outbound }
background: { size: [124, 94], position: center, color: '#000' }
post_processors:
pngquant: { quality: "75-85" }This configuration sets a quality factor range of 75 to 85 for the resulting image binary.
Note
The default executable path is /usr/bin/pngquant. If installed elsewhere
on your system, you must set the liip_imagine.pngquant.binary parameter accordingly.
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# app/config/config.yml
parameters:
liip_imagine.pngquant.binary: /your/custom/path/to/pngquantOptions
- quality:
int|int[] -
When set to an
intthis sets the maximum image quality level. When set to anint[](such as[60,80]) the first arrayintis used to define the lowest acceptable quality level and the second to define the maximum quality level (in this mode, the executable will use the least amount of colors required to meet or exceed the maximum quality, but if the conversion results in a quality below the minimum quality the converted file will be discarded and the original one used instead). - speed:
int -
The speed/quality trade-off value to use. Valid values:
1(slowest/best) through11(fastest/worst). - dithering:
bool|float -
When set to
falsethe Floyd-Steinberg dithering algorithm is completely disabled. Otherwise, when afloat, the dithering level is set.
Parameters
- liip_imagine.pngquant.binary:
string -
Sets the location of the
pngquantexecutable. Default is/usr/bin/pngquant.
This work, including the code samples, is licensed under a
Creative Commons BY-SA 3.0
license.
