Image file formats

The Python Imaging Library supports a wide variety of raster file formats. Over 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. The EPS driver can read EPS images in L, LAB, RGB and CMYK mode, but Ghostscript may convert the images to RGB mode rather than leaving them in the original color space. The EPS driver can write images in L, RGB and CMYK modes.

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 files in GIF87a by default, unless GIF89a features are used or GIF89a is already in use.

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).
transparency
Transparency color index. This key is omitted if the image is not transparent.
version
Version (either GIF87a or GIF89a).
duration
May not be present. The time to display the current frame of the GIF, in milliseconds.
loop
May not be present. The number of times the GIF should loop.

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.

im.seek() raises an EOFError if you try to seek after the last frame.

Saving

When calling save(), the following options are available:

im.save(out, save_all=True, append_images=[im1, im2, ...])
save_all
If present and true, all frames of the image will be saved. If not, then only the first frame of a multiframe image will be saved.
append_images
A list of images to append as additional frames. Each of the images in the list can be single or multiframe images. This is currently only supported for GIF, PDF, TIFF, and WebP.
duration
The display duration of each frame of the multiframe gif, in milliseconds. Pass a single integer for a constant duration, or a list or tuple to set the duration for each frame separately.
loop
Integer number of times the GIF should loop.
optimize
If present and true, attempt to compress the palette by eliminating unused colors. This is only useful if the palette can be compressed to the next smaller power of 2 elements.
palette
Use the specified palette for the saved image. The palette should be a bytes or bytearray object containing the palette entries in RGBRGB... form. It should be no more than 768 bytes. Alternately, the palette can be passed in as an PIL.ImagePalette.ImagePalette object.

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)]

ICNS

PIL reads and (macOS only) writes macOS .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), where scale is 2 for a retina icon and 1 for a standard icon. You are permitted to use this 3-tuple format for the size property if you set it before calling load(); 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 of size will be (1024, 1024)).

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), (256, 256)]. Any sizes bigger than the original size or 256 will be ignored.

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 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 and true, indicates that the encoder should make an extra pass over the image in order to select optimal encoder settings.
progressive
If present and true, 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 and true, 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, 4:2:0: Specific sampling values
  • -1: equivalent to keep
  • 0: equivalent to 4:4:4
  • 1: equivalent to 4:2:2
  • 2: equivalent to 4:2:0
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, or web_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.

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 to False, 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

For P images: Either the palette index for full transparent pixels, or a byte string with alpha values for each palette entry.

For L and RGB images, the color that represents full transparent pixels in this image.

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 and true, 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, and RGB images, this option controls what color image to mark as transparent.

For P images, this can be a either the palette index, or a byte string with alpha values for each palette entry.

dpi
A tuple of two numbers corresponding to the desired dpi in each direction.
pnginfo
A PIL.PngImagePlugin.PngInfo instance containing text tags.
compress_level
ZLIB compression level, a number between 0 and 9: 1 gives best speed, 9 gives best compression, 0 gives no compression at all. Default is 6. When optimize option is True compress_level has no effect (it is set to 9 regardless of a value passed).
icc_profile
The ICC Profile to include in the saved file.
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 installation documentation for details.

PPM

PIL reads and writes PBM, PGM and PPM files containing 1, L or RGB data.

SGI

Pillow reads and writes uncompressed L, RGB, and RGBA files.

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.

New in version 2.0.0.

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.

resolution

Image resolution as an (xres, yres) tuple, where applicable. This is a measurement in whichever unit is specified by the file.

New in version 1.1.5.

The tag_v2 attribute contains a dictionary of TIFF metadata. The keys are numerical indexes from TAGS_V2. Values are strings or numbers for single items, multiple values are returned in a tuple of values. Rational numbers are returned as a IFDRational object.

New in version 3.0.0.

For compatibility with legacy code, the tag attribute contains a dictionary of decoded TIFF fields as returned prior to version 3.0.0. Values are returned as either strings or tuples of numeric values. Rational numbers are returned as a tuple of (numerator, denominator).

Deprecated since version 3.0.0.

Saving Tiff Images

The save() method can take the following keyword arguments:

save_all

If true, Pillow will save all frames of the image to a multiframe tiff document.

New in version 3.4.0.

tiffinfo

A ImageFileDirectory_v2 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 an ImageFileDirectory_v2 object and setting the type in tagtype with the appropriate numerical value from TiffTags.TYPES.

New in version 2.3.0.

Metadata values that are of the rational type should be passed in using a IFDRational object.

New in version 3.1.0.

For compatibility with legacy code, a ImageFileDirectory_v1 object may be passed in this field. However, this is deprecated.

New in version 3.0.0.

Note

Only some tags are currently supported when writing using libtiff. The supported list is found in LIBTIFF_CORE.

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, 2 tuple of (numerator, denominator) or a IFDRational. 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 and true, instructs the WebP writer to use lossless compression.
quality
Integer, 1-100, Defaults to 80. For lossy, 0 gives the smallest size and 100 the largest. For lossless, this parameter is the amount of effort put into the compression: 0 is the fastest, but gives larger files compared to the slowest, but best, 100.
method
Quality/speed trade-off (0=fast, 6=slower-better). Defaults to 0.
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.

Saving sequences

Note

Support for animated WebP files will only be enabled if the system WebP library is v0.5.0 or later. You can check webp animation support at runtime by calling features.check(“webp_anim”).

When calling save(), the following options are available when the save_all argument is present and true.

append_images
A list of images to append as additional frames. Each of the images in the list can be single or multiframe images.
duration
The display duration of each frame, in milliseconds. Pass a single integer for a constant duration, or a list or tuple to set the duration for each frame separately.
loop
Number of times to repeat the animation. Defaults to [0 = infinite].
background
Background color of the canvas, as an RGBA tuple with values in the range of (0-255).
minimize_size
If true, minimize the output size (slow). Implicitly disables key-frame insertion.
kmin, kmax
Minimum and maximum distance between consecutive key frames in the output. The library may insert some key frames as needed to satisfy this criteria. Note that these conditions should hold: kmax > kmin and kmin >= kmax / 2 + 1. Also, if kmax <= 0, then key-frame insertion is disabled; and if kmax == 1, then all frames will be key-frames (kmin value does not matter for these special cases).
allow_mixed
If true, use mixed compression mode; the encoder heuristically chooses between lossy and lossless for each frame.

XBM

PIL reads and writes X bitmap files (mode 1).

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.

DDS

DDS is a popular container texture format used in video games and natively supported by DirectX. Currently, DXT1, DXT3, and DXT5 pixel formats are supported and only in RGBA mode.

New in version 3.4.0: DXT3

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.

FTEX

New in version 3.2.0.

The FTEX decoder reads textures used for 3D objects in Independence War 2: Edge Of Chaos. The plugin reads a single texture per file, in the compressed and uncompressed formats.

GBR

The GBR decoder reads GIMP brush files, version 1 and 2.

The open() method sets the following info properties:

comment
The brush name.
spacing
The spacing between the brushes, in pixels. Version 2 only.

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.

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

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.

Note that there may be an embedded gamma of 2.2 in MIC files.

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.

PCD

PIL reads PhotoCD files containing RGB data. This only reads the 768x512 resolution image from the file. Higher resolutions are encoded in a proprietary encoding.

PIXAR

PIL provides limited support for PIXAR raster files. The library can identify and read “dumped” RGB files.

The format code is PIXAR.

PSD

PIL identifies and reads PSD files written by Adobe Photoshop 2.5 and 3.0.

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).

When calling save(), if a multiframe image is used, by default, only the first image will be saved. To save all frames, each frame to a separate page of the PDF, the save_all parameter must be present and set to True.

XV Thumbnails

PIL can read XV thumbnail files.

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 playable 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")