







The PIL.ImageOps Module

(New in 1.1.3) The ImageOps module contains a number of
'ready-made' image processing operations.  This module is somewhat
experimental, and most operators only work on L and RGB images.

Module Contents


autocontrast(image, cutoff=0, ignore=None)  [ #PIL.ImageOps.autocontrast-function# ]

Maximize (normalize) image contrast.  This function calculates a
histogram of the input image, removes 
cutoff percent of the
lightest and darkest pixels from the histogram, and remaps the image
so that the darkest pixel becomes black (0), and the lightest
becomes white (255).


image

The image to process.

cutoff

How many percent to cut off from the histogram.

ignore

The background pixel value (use None for no background).

Returns:

An image.



colorize(image, black, white)  [ #PIL.ImageOps.colorize-function# ]

Colorize grayscale image.  The black and white
arguments should be RGB tuples; this function calculates a colour
wedge mapping all black pixels in the source image to the first
colour, and all white pixels to the second colour.


image

The image to colourize.

black

The colour to use for black input pixels.

white

The colour to use for white input pixels.

Returns:

An image.



crop(image, border=0)  [ #PIL.ImageOps.crop-function# ]

Remove border from image.  The same amount of pixels are removed
from all four sides.  This function works on all image modes.


image

The image to crop.

border

The number of pixels to remove.

Returns:

An image.



deform(image, deformer, resample=Image.BILINEAR)  [ #PIL.ImageOps.deform-function# ]

Deform the image.


image

The image to deform.

deformer

A deformer object.

resample

What resampling filter to use.

Returns:

An image.



equalize(image, mask=None)  [ #PIL.ImageOps.equalize-function# ]

Equalize the image histogram.  This function applies a non-linear
mapping to the input image, in order to create a uniform
distribution of grayscale values in the output image.


image

The image to equalize.

mask

An optional mask.  If given, only the pixels selected by
    the mask are included in the analysis.

Returns:

An image.



expand(image, border=0, fill=0)  [ #PIL.ImageOps.expand-function# ]

Add border to the image


image

The image to expand.

border

Border width, in pixels.

fill

Pixel fill value (a colour value).  Default is 0 (black).

Returns:

An image.



fit(image, size, method=Image.NEAREST, bleed=0.0, centering=(0.5, 0.5))  [ #PIL.ImageOps.fit-function# ]

Returns a sized and cropped version of the image, cropped to the
requested aspect ratio and size.

The 
fit function was contributed by Kevin Cazabon.


size

The requested output size in pixels, given as a
    (width, height) tuple.

method

What resampling method to use.  Default is Image.NEAREST.

bleed

Remove a border around the outside of the image (from all
    four edges.  The value is a decimal percentage (use 0.01 for one
    percent).  The default value is 0 (no border).

centering

Control the cropping position.  Use (0.5, 0.5) for
    center cropping (e.g. if cropping the width, take 50% off of the
    left side, and therefore 50% off the right side).  (0.0, 0.0)
    will crop from the top left corner (i.e. if cropping the width,
    take all of the crop off of the right side, and if cropping the
    height, take all of it off the bottom).  (1.0, 0.0) will crop
    from the bottom left corner, etc. (i.e. if cropping the width,
    take all of the crop off the left side, and if cropping the height
    take none from the top, and therefore all off the bottom).

Returns:

An image.



flip(image)  [ #PIL.ImageOps.flip-function# ]

Flip the image vertically (top to bottom).


image

The image to flip.

Returns:

An image.



grayscale(image)  [ #PIL.ImageOps.grayscale-function# ]

Convert the image to grayscale.


image

The image to convert.

Returns:

An image.



invert(image)  [ #PIL.ImageOps.invert-function# ]

Invert (negate) the image.


image

The image to invert.

Returns:

An image.



mirror(image)  [ #PIL.ImageOps.mirror-function# ]

Flip image horizontally (left to right).


image

The image to mirror.

Returns:

An image.



posterize(image, bits)  [ #PIL.ImageOps.posterize-function# ]

Reduce the number of bits for each colour channel.


image

The image to posterize.

bits

The number of bits to keep for each channel (1-8).

Returns:

An image.



solarize(image, threshold=128)  [ #PIL.ImageOps.solarize-function# ]

Invert all pixel values above a threshold.


image

The image to posterize.

threshold

All pixels above this greyscale level are inverted.

Returns:

An image.





