Image file formats¶
The Python Imaging Library supports a wide variety of raster file formats. Nearly 30 different file formats can be identified and read by the library. Write support is less extensive, but most common interchange and presentation formats are supported.
The open()
function identifies files from their
contents, not their names, but the save()
method
looks at the name to determine which format to use, unless the format is given
explicitly.
Fully supported formats¶
BMP¶
PIL reads and writes Windows and OS/2 BMP files containing 1
, L
, P
,
or RGB
data. 16-colour images are read as P
images. Run-length encoding
is not supported.
The open()
method sets the following
info
properties:
- compression
- Set to
bmp_rle
if the file is run-length encoded.
EPS¶
PIL identifies EPS files containing image data, and can read files that contain embedded raster images (ImageData descriptors). If Ghostscript is available, other EPS files can be read as well. The EPS driver can also write EPS images.
If Ghostscript is available, you can call the load()
method with the following parameter to affect how Ghostscript renders the EPS
- scale
Affects the scale of the resultant rasterized image. If the EPS suggests that the image be rendered at 100px x 100px, setting this parameter to 2 will make the Ghostscript render a 200px x 200px image instead. The relative position of the bounding box is maintained:
im = Image.open(...) im.size #(100,100) im.load(scale=2) im.size #(200,200)
GIF¶
PIL reads GIF87a and GIF89a versions of the GIF file format. The library writes
run-length encoded GIF87a files. Note that GIF files are always read as
grayscale (L
) or palette mode (P
) images.
The open()
method sets the following
info
properties:
- background
- Default background color (a palette color index).
- duration
- Time between frames in an animation (in milliseconds).
- transparency
- Transparency color index. This key is omitted if the image is not transparent.
- version
- Version (either
GIF87a
orGIF89a
).
Reading sequences¶
The GIF loader supports the seek()
and tell()
methods. You can seek to the next frame (im.seek(im.tell() + 1
), or rewind
the file by seeking to the first frame. Random access is not supported.
Reading local images¶
The GIF loader creates an image memory the same size as the GIF file’s logical
screen size, and pastes the actual pixel data (the local image) into this
image. If you only want the actual pixel rectangle, you can manipulate the
size
and tile
attributes before loading the file:
im = Image.open(...)
if im.tile[0][0] == "gif":
# only read the first "local image" from this GIF file
tag, (x0, y0, x1, y1), offset, extra = im.tile[0]
im.size = (x1 - x0, y1 - y0)
im.tile = [(tag, (0, 0) + im.size, offset, extra)]
IM¶
IM is a format used by LabEye and other applications based on the IFUNC image processing library. The library reads and writes most uncompressed interchange versions of this format.
IM is the only format that can store all internal PIL formats.
JPEG¶
PIL reads JPEG, JFIF, and Adobe JPEG files containing L
, RGB
, or
CMYK
data. It writes standard and progressive JFIF files.
Using the draft()
method, you can speed things up by
converting RGB
images to L
, and resize images to 1/2, 1/4 or 1/8 of
their original size while loading them. The draft()
method also configures the JPEG decoder to trade some quality for speed.
The open()
method may set the following
info
properties if available:
- jfif
- JFIF application marker found. If the file is not a JFIF file, this key is not present.
- jfif_version
- A tuple representing the jfif version, (major version, minor version).
- jfif_density
- A tuple representing the pixel density of the image, in units specified by jfif_unit.
- jfif_unit
Units for the jfif_density:
- 0 - No Units
- 1 - Pixels per Inch
- 2 - Pixels per Centimeter
- dpi
- A tuple representing the reported pixel density in pixels per inch, if the file is a jfif file and the units are in inches.
- adobe
- Adobe application marker found. If the file is not an Adobe JPEG file, this key is not present.
- adobe_transform
- Vendor Specific Tag.
- progression
- Indicates that this is a progressive JPEG file.
- icc-profile
- The ICC color profile for the image.
- exif
- Raw EXIF data from the image.
The save()
method supports the following options:
- quality
- The image quality, on a scale from 1 (worst) to 95 (best). The default is 75. Values above 95 should be avoided; 100 disables portions of the JPEG compression algorithm, and results in large files with hardly any gain in image quality.
- optimize
- If present, indicates that the encoder should make an extra pass over the image in order to select optimal encoder settings.
- progressive
- If present, indicates that this image should be stored as a progressive JPEG file.
- dpi
- A tuple of integers representing the pixel density,
(x,y)
. - icc-profile
If present, the image is stored with the provided ICC profile. If this parameter is not provided, the image will be saved with no profile attached. To preserve the existing profile:
im.save(filename, 'jpeg', icc_profile=im.info.get('icc_profile'))
- exif
- If present, the image will be stored with the provided raw EXIF data.
- subsampling
If present, sets the subsampling for the encoder.
keep
: Only valid for JPEG files, will retain the original image setting.4:4:4
,4:2:2
,4:1:1
: Specific sampling values-1
: equivalent tokeep
0
: equivalent to4:4:4
1
: equivalent to4:2:2
2
: equivalent to4:1:1
- qtables
If present, sets the qtables for the encoder. This is listed as an advanced option for wizards in the JPEG documentation. Use with caution.
qtables
can be one of several types of values:- a string, naming a preset, e.g.
keep
,web_low
, orweb_high
- a list, tuple, or dictionary (with integer keys = range(len(keys))) of lists of 64 integers. There must be between 2 and 4 tables.
New in version 2.5.0.
- a string, naming a preset, e.g.
Note
To enable JPEG support, you need to build and install the IJG JPEG library before building the Python Imaging Library. See the distribution README for details.
JPEG 2000¶
New in version 2.4.0.
PIL reads and writes JPEG 2000 files containing L
, LA
, RGB
or
RGBA
data. It can also read files containing YCbCr
data, which it
converts on read into RGB
or RGBA
depending on whether or not there is
an alpha channel. PIL supports JPEG 2000 raw codestreams (.j2k
files), as
well as boxed JPEG 2000 files (.j2p
or .jpx
files). PIL does not
support files whose components have different sampling frequencies.
When loading, if you set the mode
on the image prior to the
load()
method being invoked, you can ask PIL to
convert the image to either RGB
or RGBA
rather than choosing for
itself. It is also possible to set reduce
to the number of resolutions to
discard (each one reduces the size of the resulting image by a factor of 2),
and layers
to specify the number of quality layers to load.
The save()
method supports the following options:
- offset
- The image offset, as a tuple of integers, e.g. (16, 16)
- tile_offset
- The tile offset, again as a 2-tuple of integers.
- tile_size
- The tile size as a 2-tuple. If not specified, or if set to None, the image will be saved without tiling.
- quality_mode
- Either “rates” or “dB” depending on the units you want to use to specify image quality.
- quality_layers
- A sequence of numbers, each of which represents either an approximate size reduction (if quality mode is “rates”) or a signal to noise ratio value in decibels. If not specified, defaults to a single layer of full quality.
- num_resolutions
- The number of different image resolutions to be stored (which corresponds to the number of Discrete Wavelet Transform decompositions plus one).
- codeblock_size
- The code-block size as a 2-tuple. Minimum size is 4 x 4, maximum is 1024 x 1024, with the additional restriction that no code-block may have more than 4096 coefficients (i.e. the product of the two numbers must be no greater than 4096).
- precinct_size
- The precinct size as a 2-tuple. Must be a power of two along both axes, and must be greater than the code-block size.
- irreversible
- If
True
, use the lossy Irreversible Color Transformation followed by DWT 9-7. Defaults toFalse
, which means to use the Reversible Color Transformation with DWT 5-3. - progression
- Controls the progression order; must be one of
"LRCP"
,"RLCP"
,"RPCL"
,"PCRL"
,"CPRL"
. The letters stand for Component, Position, Resolution and Layer respectively and control the order of encoding, the idea being that e.g. an image encoded using LRCP mode can have its quality layers decoded as they arrive at the decoder, while one encoded using RLCP mode will have increasing resolutions decoded as they arrive, and so on. - cinema_mode
- Set the encoder to produce output compliant with the digital cinema
specifications. The options here are
"no"
(the default),"cinema2k-24"
for 24fps 2K,"cinema2k-48"
for 48fps 2K, and"cinema4k-24"
for 24fps 4K. Note that for compliant 2K files, at least one of your image dimensions must match 2048 x 1080, while for compliant 4K files, at least one of the dimensions must match 4096 x 2160.
Note
To enable JPEG 2000 support, you need to build and install the OpenJPEG library, version 2.0.0 or higher, before building the Python Imaging Library.
Windows users can install the OpenJPEG binaries available on the
OpenJPEG website, but must add them to their PATH in order to use PIL (if
you fail to do this, you will get errors about not being able to load the
_imaging
DLL).
MSP¶
PIL identifies and reads MSP files from Windows 1 and 2. The library writes uncompressed (Windows 1) versions of this format.
PCX¶
PIL reads and writes PCX files containing 1
, L
, P
, or RGB
data.
PNG¶
PIL identifies, reads, and writes PNG files containing 1
, L
, P
,
RGB
, or RGBA
data. Interlaced files are supported as of v1.1.7.
The open()
method sets the following
info
properties, when appropriate:
- gamma
- Gamma, given as a floating point number.
- transparency
- Transparency color index. This key is omitted if the image is not a transparent palette image.
Open
also sets Image.text
to a list of the values of the
tEXt
, zTXt
, and iTXt
chunks of the PNG image. Individual
compressed chunks are limited to a decompressed size of
PngImagePlugin.MAX_TEXT_CHUNK
, by default 1MB, to prevent
decompression bombs. Additionally, the total size of all of the text
chunks is limited to PngImagePlugin.MAX_TEXT_MEMORY
, defaulting to
64MB.
The save()
method supports the following options:
- optimize
- If present, instructs the PNG writer to make the output file as small as possible. This includes extra processing in order to find optimal encoder settings.
- transparency
- For
P
,L
, andRGB
images, this option controls what color image to mark as transparent. - dpi
- A tuple of two numbers corresponding to the desired dpi in each direction.
- pnginfo
- A
PIL.PngImagePlugin.PngInfo
instance containing text tags. - bits (experimental)
- For
P
images, this option controls how many bits to store. If omitted, the PNG writer uses 8 bits (256 colors). - dictionary (experimental)
- Set the ZLIB encoder dictionary.
Note
To enable PNG support, you need to build and install the ZLIB compression library before building the Python Imaging Library. See the distribution README for details.
PPM¶
PIL reads and writes PBM, PGM and PPM files containing 1
, L
or RGB
data.
SPIDER¶
PIL reads and writes SPIDER image files of 32-bit floating point data (“F;32F”).
PIL also reads SPIDER stack files containing sequences of SPIDER images. The
seek()
and tell()
methods are supported, and
random access is allowed.
The open()
method sets the following attributes:
- format
- Set to
SPIDER
- istack
- Set to 1 if the file is an image stack, else 0.
- nimages
- Set to the number of images in the stack.
A convenience method, convert2byte()
, is provided for
converting floating point data to byte data (mode L
):
im = Image.open('image001.spi').convert2byte()
Writing files in SPIDER format¶
The extension of SPIDER files may be any 3 alphanumeric characters. Therefore the output format must be specified explicitly:
im.save('newimage.spi', format='SPIDER')
For more information about the SPIDER image processing package, see the SPIDER homepage at Wadsworth Center.
TIFF¶
PIL reads and writes TIFF files. It can read both striped and tiled images, pixel and plane interleaved multi-band images, and either uncompressed, or Packbits, LZW, or JPEG compressed images.
If you have libtiff and its headers installed, PIL can read and write many more kinds of compressed TIFF files. If not, PIL will always write uncompressed files.
The open()
method sets the following
info
properties:
- compression
- Compression mode.
- dpi
Image resolution as an (xdpi, ydpi) tuple, where applicable. You can use the
tag
attribute to get more detailed information about the image resolution.New in version 1.1.5.
In addition, the tag
attribute contains a
dictionary of decoded TIFF fields. Values are stored as either strings or
tuples. Note that only short, long and ASCII tags are correctly unpacked by
this release.
Saving Tiff Images¶
The save()
method can take the following keyword arguments:
- tiffinfo
A
ImageFileDirectory
object or dict object containing tiff tags and values. The TIFF field type is autodetected for Numeric and string values, any other types require using anImageFileDirectory
object and setting the type intagtype
with the appropriate numerical value fromTiffTags.TYPES
.New in version 2.3.0.
- compression
- A string containing the desired compression method for the
- file. (valid only with libtiff installed) Valid compression
methods are:
[None, "tiff_ccitt", "group3", "group4", "tiff_jpeg", "tiff_adobe_deflate", "tiff_thunderscan", "tiff_deflate", "tiff_sgilog", "tiff_sgilog24", "tiff_raw_16"]
These arguments to set the tiff header fields are an alternative to using the general tags available through tiffinfo.
description
software
date_time
artist
- copyright
- Strings
- resolution_unit
- A string of “inch”, “centimeter” or “cm”
resolution
x_resolution
y_resolution
- dpi
- Either a Float, Integer, or 2 tuple of (numerator, denominator). Resolution implies an equal x and y resolution, dpi also implies a unit of inches.
WebP¶
PIL reads and writes WebP files. The specifics of PIL’s capabilities with this format are currently undocumented.
The save()
method supports the following options:
- lossless
- If present, instructs the WEBP writer to use lossless compression.
- quality
- Integer, 1-100, Defaults to 80. Sets the quality level for lossy compression.
- icc_procfile
- The ICC Profile to include in the saved file. Only supported if the system webp library was built with webpmux support.
- exif
- The exif data to include in the saved file. Only supported if the system webp library was built with webpmux support.
XBM¶
PIL reads and writes X bitmap files (mode 1
).
XV Thumbnails¶
PIL can read XV thumbnail files.
Read-only formats¶
CUR¶
CUR is used to store cursors on Windows. The CUR decoder reads the largest available cursor. Animated cursors are not supported.
DCX¶
DCX is a container file format for PCX files, defined by Intel. The DCX format
is commonly used in fax applications. The DCX decoder can read files containing
1
, L
, P
, or RGB
data.
When the file is opened, only the first image is read. You can use
seek()
or ImageSequence
to read other images.
FLI, FLC¶
PIL reads Autodesk FLI and FLC animations.
The open()
method sets the following
info
properties:
- duration
- The delay (in milliseconds) between each frame.
FPX¶
PIL reads Kodak FlashPix files. In the current version, only the highest resolution image is read from the file, and the viewing transform is not taken into account.
Note
To enable full FlashPix support, you need to build and install the IJG JPEG library before building the Python Imaging Library. See the distribution README for details.
GBR¶
The GBR decoder reads GIMP brush files.
The open()
method sets the following
info
properties:
- description
- The brush name.
GD¶
PIL reads uncompressed GD files. Note that this file format cannot be
automatically identified, so you must use PIL.GdImageFile.open()
to
read such a file.
The open()
method sets the following
info
properties:
- transparency
- Transparency color index. This key is omitted if the image is not transparent.
ICO¶
ICO is used to store icons on Windows. The largest available icon is read.
The save()
method supports the following options:
- sizes
- A list of sizes including in this ico file; these are a 2-tuple,
(width, height)
; Default to[(16, 16), (24, 24), (32, 32), (48, 48), (64, 64), (128, 128), (255, 255)]
. Any size is bigger then the original size or 255 will be ignored.
ICNS¶
PIL reads Mac OS X .icns
files. By default, the largest available icon is
read, though you can override this by setting the size
property before calling load()
. The
open()
method sets the following
info
property:
- sizes
- A list of supported sizes found in this icon file; these are a
3-tuple,
(width, height, scale)
, wherescale
is 2 for a retina icon and 1 for a standard icon. You are permitted to use this 3-tuple format for thesize
property if you set it before callingload()
; after loading, the size will be reset to a 2-tuple containing pixel dimensions (so, e.g. if you ask for(512, 512, 2)
, the final value ofsize
will be(1024, 1024)
).
IMT¶
PIL reads Image Tools images containing L
data.
IPTC/NAA¶
PIL provides limited read support for IPTC/NAA newsphoto files.
MCIDAS¶
PIL identifies and reads 8-bit McIdas area files.
MIC (read only)
PIL identifies and reads Microsoft Image Composer (MIC) files. When opened, the
first sprite in the file is loaded. You can use seek()
and
tell()
to read other sprites from the file.
MPO¶
Pillow identifies and reads Multi Picture Object (MPO) files, loading the primary
image when first opened. The seek()
and tell()
methods may be used to read other pictures from the file. The pictures are
zero-indexed and random access is supported.
MIC (read only)
Pillow identifies and reads Microsoft Image Composer (MIC) files. When opened, the
first sprite in the file is loaded. You can use seek()
and
tell()
to read other sprites from the file.
PCD¶
PIL reads PhotoCD files containing RGB
data. By default, the 768x512
resolution is read. You can use the draft()
method to
read the lower resolution versions instead, thus effectively resizing the image
to 384x256 or 192x128. Higher resolutions cannot be read by the Python Imaging
Library.
PSD¶
PIL identifies and reads PSD files written by Adobe Photoshop 2.5 and 3.0.
SGI¶
PIL reads uncompressed L
, RGB
, and RGBA
files.
TGA¶
PIL reads 24- and 32-bit uncompressed and run-length encoded TGA files.
WAL¶
New in version 1.1.4.
PIL reads Quake2 WAL texture files.
Note that this file format cannot be automatically identified, so you must use
the open function in the WalImageFile
module to read files in
this format.
By default, a Quake2 standard palette is attached to the texture. To override the palette, use the putpalette method.
XPM¶
PIL reads X pixmap files (mode P
) with 256 colors or less.
The open()
method sets the following
info
properties:
- transparency
- Transparency color index. This key is omitted if the image is not transparent.
Write-only formats¶
PALM¶
PIL provides write-only support for PALM pixmap files.
The format code is Palm
, the extension is .palm
.
PDF¶
PIL can write PDF (Acrobat) images. Such images are written as binary PDF 1.1 files, using either JPEG or HEX encoding depending on the image mode (and whether JPEG support is available or not).
PIXAR (read only)¶
PIL provides limited support for PIXAR raster files. The library can identify and read “dumped” RGB files.
The format code is PIXAR
.
Identify-only formats¶
BUFR¶
New in version 1.1.3.
PIL provides a stub driver for BUFR files.
To add read or write support to your application, use
PIL.BufrStubImagePlugin.register_handler()
.
FITS¶
New in version 1.1.5.
PIL provides a stub driver for FITS files.
To add read or write support to your application, use
PIL.FitsStubImagePlugin.register_handler()
.
GRIB¶
New in version 1.1.5.
PIL provides a stub driver for GRIB files.
The driver requires the file to start with a GRIB header. If you have files with embedded GRIB data, or files with multiple GRIB fields, your application has to seek to the header before passing the file handle to PIL.
To add read or write support to your application, use
PIL.GribStubImagePlugin.register_handler()
.
HDF5¶
New in version 1.1.5.
PIL provides a stub driver for HDF5 files.
To add read or write support to your application, use
PIL.Hdf5StubImagePlugin.register_handler()
.
MPEG¶
PIL identifies MPEG files.
WMF¶
PIL can identify placable WMF files.
In PIL 1.1.4 and earlier, the WMF driver provides some limited rendering support, but not enough to be useful for any real application.
In PIL 1.1.5 and later, the WMF driver is a stub driver. To add WMF read or
write support to your application, use
PIL.WmfImagePlugin.register_handler()
to register a WMF handler.
from PIL import Image
from PIL import WmfImagePlugin
class WmfHandler:
def open(self, im):
...
def load(self, im):
...
return image
def save(self, im, fp, filename):
...
wmf_handler = WmfHandler()
WmfImagePlugin.register_handler(wmf_handler)
im = Image.open("sample.wmf")