4.3.0

API Changes

Deprecations

Several undocumented functions in ImageOps have been deprecated: gaussian_blur, gblur, unsharp_mask, usm and box_blur. Use the equivalent operations in ImageFilter instead. These functions will be removed in a future release.

TIFF Metadata Changes

  • TIFF tags with unknown type/quantity now default to being bare values if they are 1 element, where previously they would be a single element tuple. This is only with the new api, not the legacy api. This normalizes the handling of fields, so that the metadata with inferred or image specified counts are handled the same as metadata with count specified in the TIFF spec.
  • The PhotoshopInfo, XMP, and JPEGTables tags now have a defined type (bytes) and a count of 1.
  • The ImageJMetaDataByteCounts tag now has an arbitrary number of items, as there can be multiple items, one for UTF-8, and one for UTF-16.

Core Image API Changes

These are internal functions that should not have been used by user code, but they were accessible from the python layer.

Debugging code within Image.core.grabclipboard was removed. It had been marked as will be removed in future versions since PIL. When enabled, it identified the format of the clipboard data.

The PIL.Image.core.copy and PIL.Image.Image.im.copy2 methods have been removed.

The PIL.Image.core.getcount methods have been removed, use PIL.Image.core.get_stats()['new_count'] property instead.

API Additions

Get One Channel From Image

A new method PIL.Image.Image.getchannel() has been added to return a single channel by index or name. For example, image.getchannel("A") will return alpha channel as separate image. getchannel should work up to 6 times faster than image.split()[0] in previous Pillow versions.

Box Blur

A new filter, PIL.ImageFilter.BoxBlur, has been added. This is a filter with similar results to a Gaussian blur, but is much faster.

Partial Resampling

Added new argument box for PIL.Image.Image.resize(). This argument defines a source rectangle from within the source image to be resized. This is very similar to the image.crop(box).resize(size) sequence except that box can be specified with subpixel accuracy.

New Transpose Operation

The Image.TRANSVERSE operation has been added to PIL.Image.Image.transpose(). This is equivalent to a transpose operation about the opposite diagonal.

Multiband Filters

There is a new PIL.ImageFilter.MultibandFilter base class for image filters that can run on all channels of an image in one operation. The original PIL.ImageFilter.Filter class remains for image filters that can process only single band images, or require splitting of channels prior to filtering.

Other Changes

Loading 16-bit TIFF Images

Pillow now can read 16-bit multichannel TIFF files including files with alpha transparency. The image data is truncated to 8-bit precision.

Pillow now can read 16-bit signed integer single channel TIFF files. The image data is promoted to 32-bit for storage and processing.

SGI Images

Pillow can now read and write uncompressed 16-bit multichannel SGI images to and from RGB and RGBA formats. The image data is truncated to 8-bit precision.

Pillow can now read RLE encoded SGI images in both 8 and 16-bit precision.

Performance

This release contains several performance improvements:

  • Many memory bandwidth-bounded operations such as crop, image allocation, conversion, split into bands and merging from bands are up to 2x faster.
  • Upscaling of multichannel images (such as RGB) is accelerated by 5-10%
  • JPEG loading is accelerated up to 15% and JPEG saving up to 20% when using a recent version of libjpeg-turbo.
  • Image.transpose has been accelerated 15% or more by using a cache friendly algorithm.
  • ImageFilters based on Kernel convolution are significantly faster due to the new MultibandFilter feature.
  • All memory allocation for images is now done in blocks, rather than falling back to an allocation for each scan line for images larger than the block size.

CMYK Conversion

The basic CMYK->RGB conversion has been tweaked to match the formula from Google Chrome. This produces an image that is generally lighter than the previous formula, and more in line with what color managed applications produce.