Staging
v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: 1da43e5e916949c8e849e656d9d05fa4b9d6836c authored by Benjamin Peterson on 26 June 2009, 13:21:52 UTC
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
Tip revision: 1da43e5
imghdr.rst
:mod:`imghdr` --- Determine the type of an image
================================================
.. module:: imghdr
:synopsis: Determine the type of image contained in a file or byte stream.
The :mod:`imghdr` module determines the type of image contained in a file or
byte stream.
The :mod:`imghdr` module defines the following function:
.. function:: what(filename, h=None)
Tests the image data contained in the file named by *filename*, and returns a
string describing the image type. If optional *h* is provided, the *filename*
is ignored and *h* is assumed to contain the byte stream to test.
The following image types are recognized, as listed below with the return value
from :func:`what`:
+------------+-----------------------------------+
| Value | Image format |
+============+===================================+
| ``'rgb'`` | SGI ImgLib Files |
+------------+-----------------------------------+
| ``'gif'`` | GIF 87a and 89a Files |
+------------+-----------------------------------+
| ``'pbm'`` | Portable Bitmap Files |
+------------+-----------------------------------+
| ``'pgm'`` | Portable Graymap Files |
+------------+-----------------------------------+
| ``'ppm'`` | Portable Pixmap Files |
+------------+-----------------------------------+
| ``'tiff'`` | TIFF Files |
+------------+-----------------------------------+
| ``'rast'`` | Sun Raster Files |
+------------+-----------------------------------+
| ``'xbm'`` | X Bitmap Files |
+------------+-----------------------------------+
| ``'jpeg'`` | JPEG data in JFIF or Exif formats |
+------------+-----------------------------------+
| ``'bmp'`` | BMP files |
+------------+-----------------------------------+
| ``'png'`` | Portable Network Graphics |
+------------+-----------------------------------+
You can extend the list of file types :mod:`imghdr` can recognize by appending
to this variable:
.. data:: tests
A list of functions performing the individual tests. Each function takes two
arguments: the byte-stream and an open file-like object. When :func:`what` is
called with a byte-stream, the file-like object will be ``None``.
The test function should return a string describing the image type if the test
succeeded, or ``None`` if it failed.
Example::
>>> import imghdr
>>> imghdr.what('/tmp/bass.gif')
'gif'