The imghdr module determines the type of image contained in a
file or byte stream.
The imghdr module defines the following function:
- what (filename[, h])
-
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 what:
- ``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 JIFF format
You can extend the list of file types imghdr can recognize by
appending to this variable:
- tests
-
A list of functions performing the individual tests. Each function
takes two arguments: the byte-stream and an open file-like object.
When 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'
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