ImageFilter
Module¶
The ImageFilter
module contains definitions for a pre-defined set of
filters, which can be be used with the Image.filter()
method.
Example: Filter an image¶
from PIL import ImageFilter
im1 = im.filter(ImageFilter.BLUR)
im2 = im.filter(ImageFilter.MinFilter(3))
im3 = im.filter(ImageFilter.MinFilter) # same as MinFilter(3)
Filters¶
The current version of the library provides the following set of predefined image enhancement filters:
- BLUR
- CONTOUR
- DETAIL
- EDGE_ENHANCE
- EDGE_ENHANCE_MORE
- EMBOSS
- FIND_EDGES
- SMOOTH
- SMOOTH_MORE
- SHARPEN
-
class
PIL.ImageFilter.
UnsharpMask
(radius=2, percent=150, threshold=3)[源代码]¶ Unsharp mask filter.
See Wikipedia’s entry on digital unsharp masking for an explanation of the parameters.
参数: - radius – Blur Radius
- percent – Unsharp strength, in percent
- threshold – Threshold controls the minimum brightness change that will be sharpened
-
class
PIL.ImageFilter.
Kernel
(size, kernel, scale=None, offset=0)[源代码]¶ Create a convolution kernel. The current version only supports 3x3 and 5x5 integer and floating point kernels.
In the current version, kernels can only be applied to “L” and “RGB” images.
参数: - size – Kernel size, given as (width, height). In the current version, this must be (3,3) or (5,5).
- kernel – A sequence containing kernel weights.
- scale – Scale factor. If given, the result for each pixel is divided by this value. the default is the sum of the kernel weights.
- offset – Offset. If given, this value is added to the result, after it has been divided by the scale factor.
-
class
PIL.ImageFilter.
RankFilter
(size, rank)[源代码]¶ Create a rank filter. The rank filter sorts all pixels in a window of the given size, and returns the rank’th value.
参数: - size – The kernel size, in pixels.
- rank – What pixel value to pick. Use 0 for a min filter,
size * size / 2
for a median filter,size * size - 1
for a max filter, etc.
-
class
PIL.ImageFilter.
MedianFilter
(size=3)[源代码]¶ Create a median filter. Picks the median pixel value in a window with the given size.
参数: size – The kernel size, in pixels.
-
class
PIL.ImageFilter.
MinFilter
(size=3)[源代码]¶ Create a min filter. Picks the lowest pixel value in a window with the given size.
参数: size – The kernel size, in pixels.
-
class
PIL.ImageFilter.
MaxFilter
(size=3)[源代码]¶ Create a max filter. Picks the largest pixel value in a window with the given size.
参数: size – The kernel size, in pixels.
-
class
PIL.ImageFilter.
ModeFilter
(size=3)[源代码]¶ Create a mode filter. Picks the most frequent pixel value in a box with the given size. Pixel values that occur only once or twice are ignored; if no pixel value occurs more than twice, the original pixel value is preserved.
参数: size – The kernel size, in pixels.