Pillow: Tried to find the detailed implementation of ImageFilter

[anonymous530]

What did you do?

Tried to find the detailed implementation of ImageFilter, but I can't figure out where filterargs are used? That is, I can't figure out the implementation detail for image filter. I just saw the filter function in Image.py and ImageFilter in ImageFilter.py , but still could't find the detailed implementation. Could you help me?

What did you expect to happen?

Tried to find the detailed implementation of ImageFilter.

[anonymous530]

Is the ImageFilter implemented in libImaging/Filter.c ?

[radarhere]

Starting from code -

from PIL import Image, ImageFilter
im = Image.new("RGB", (100, 100), "#f00")
im.filter(ImageFilter.BLUR)

im.filter calls -
https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/PIL/Image.py#L1185

Which then calls this, or a similar line -

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/PIL/Image.py#L1205

Since filter is ImageFilter.BLUR that was passed in, the filter method of ImageFilter.BLUR is called. Note that self.im is not a PIL.Image.Image instance, but an ImagingCore object.

ImageFilter.BLUR inherits ImageFilter.BuiltinFilter - https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/PIL/ImageFilter.py#L212

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/PIL/ImageFilter.py#L36-L40

image being an ImagingCore object, this moves into the C code.

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/_imaging.c#L3194

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/_imaging.c#L1004-L1005

This parses the filterargs that were passed in -

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/_imaging.c#L1014-L1015

and calls -

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/_imaging.c#L1032

leading to

https://github.com/python-pillow/Pillow/blob/169961649d1d946c95155d4f046b8cbcdff49e61/src/libImaging/Filter.c#L316-L317

So yes, src/libImaging/Filter.c

[anonymous530]

Thanks