ImageFilter Module

Note

All source images in this document are derived from https://www.pexels.com (CC0 License).

Filters

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#filters, http://effbot.org/imagingbook/imagefilter.htm#filters

srcimg05.jpg

from PIL import Image
from PIL import ImageFilter
from PIL.ImageFilter import (
    BLUR, CONTOUR, DETAIL, EDGE_ENHANCE, EDGE_ENHANCE_MORE,
    EMBOSS, FIND_EDGES, SMOOTH, SMOOTH_MORE, SHARPEN
    )
img = Image.open('data/srcimg05.jpg')
for f in (
    BLUR, CONTOUR, DETAIL, EDGE_ENHANCE, EDGE_ENHANCE_MORE,
    EMBOSS, FIND_EDGES, SMOOTH, SMOOTH_MORE, SHARPEN):

    img.filter(f).save(
        "result/ImageFilter_predefs_{}_01.jpg".format(
            f.name.replace(" ", "-")))

Blur	Contour	Detail	Edge-enhance	Edge-enhance More
Emboss	Find Edges	Smooth	Smooth More	Sharpen

class GaussianBlur

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.GaussianBlur

srcimg05.jpg

from PIL import Image from PIL import ImageFilter from PIL.ImageFilter import ( GaussianBlur ) simg = Image.open('data/srcimg05.jpg') # defaut: radius=2 dimg = simg.filter(GaussianBlur(radius=10)) dimg.save("result/ImageFilter_GaussianBlur_10.jpg")

class UnsharpMask

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.UnsharpMask

srcimg07.jpg

from PIL import Image from PIL import ImageFilter from PIL.ImageFilter import ( UnsharpMask ) simg = Image.open('data/srcimg07.jpg') # defaut: radius=2, percent=150, threshold=3 dimg = simg.filter(UnsharpMask(radius=2, percent=150, threshold=3)) dimg.save("result/ImageFilter_UnsharpMask_2_150_3.jpg")

class Kernel

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.Kernel, http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.Kernel

srcimg05.jpg

from PIL import Image from PIL import ImageFilter img = Image.open('data/srcimg05.jpg') # one kind of emboss km = ( -2, -1, 0, -1, 1, 1, 0, 1, 2 ) k = ImageFilter.Kernel( size=(3, 3), kernel=km, scale=sum(km), # default offset=0 # default ) img.filter(k).save( "result/ImageFilter_Kernel_01.jpg")

from PIL import Image from PIL import ImageFilter import numpy as np img = Image.open('data/srcimg05.jpg') # Gaussian blur 5 x 5 (approximation) km = np.array(( (1, 4, 6, 4, 1), (4, 16, 24, 16, 4), (6, 24, 36, 24, 6), (4, 16, 24, 16, 4), (1, 4, 6, 4, 1), )) / 256. k = ImageFilter.Kernel( size=km.shape, kernel=km.flatten(), scale=np.sum(km), # default offset=0 # default ) img.filter(k).save( "result/ImageFilter_Kernel_02.jpg")

class RankFilter, MedianFilter, MinFilter, MaxFilter

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.RankFilter, https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.MedianFilter, https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.MinFilter, https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.MaxFilter http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.RankFilter, http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.MedianFilter, http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.MinFilter, http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.MaxFilter

Note

MedianFilter, MinFilter, and MaxFilter are subclasses of RankFilter.

srcimg06.jpg

from PIL import Image
from PIL import ImageFilter
from PIL.ImageFilter import (
    RankFilter, MedianFilter, MinFilter, MaxFilter
    )
simg = Image.open('data/srcimg06.jpg')

#
dimg = simg.filter(RankFilter(size=9, rank=2))
dimg.save("result/ImageFilter_RankFilter_9_2.jpg")
#
dimg = simg.filter(MinFilter(size=9))
dimg.save("result/ImageFilter_MinFilter_9.jpg")
#
dimg = simg.filter(MedianFilter(size=9))
dimg.save("result/ImageFilter_MedianFilter_9.jpg")
#
dimg = simg.filter(MaxFilter(size=9))
dimg.save("result/ImageFilter_MaxFilter_9.jpg")

RankFilter(size=9, rank=2)

MinFilter(size=9)

MedianFilter(size=9)

MaxFilter(size=9)

class ModeFilter

doc

https://pillow.readthedocs.io/en/latest/reference/ImageFilter.html#PIL.ImageFilter.ModeFilter, http://effbot.org/imagingbook/imagefilter.htm#tag-ImageFilter.ModeFilter

srcimg06.jpg

from PIL import Image from PIL import ImageFilter from PIL.ImageFilter import ( ModeFilter ) simg = Image.open('data/srcimg06.jpg') # dimg = simg.filter(ModeFilter(size=9)) dimg.save("result/ImageFilter_ModeFilter_9.jpg")