The module jpeg provides access to the jpeg compressor and
decompressor written by the Independent JPEG Group
(IJG). JPEG is a standard for compressing pictures; it is defined in ISO 10918. For
details on JPEG or the Independent JPEG Group software refer to the JPEG standard or the
documentation provided with the software.
A portable interface to JPEG image files is available with the Python Imaging Library (PIL)
by Fredrik Lundh. Information on PIL is available at http://www.pythonware.com/products/pil/.
The jpeg module defines an exception and some functions.
- exception error
- Exception raised by compress() and decompress()
in case of errors.
- Treat data as a pixmap of width w and height h, with b
bytes per pixel. The data is in SGI GL order, so the first pixel is in the lower-left
corner. This means that gl.lrectread() return data can
immediately be passed to compress(). Currently only 1 byte and 4
byte pixels are allowed, the former being treated as greyscale and the latter as RGB
color. compress() returns a string that contains the compressed
picture, in JFIF
- Data is a string containing a picture in JFIF
format. It returns a tuple
(data, width, height,
bytesperpixel). Again, the data is suitable to pass to gl.lrectwrite().
- Set various options. Subsequent compress() and decompress() calls will use these options. The following options are
|Force output to be grayscale, even if input is RGB.
|Set the quality of the compressed image to a value between
100 (default is
75). This only affects compression.
|Perform Huffman table optimization. Takes longer, but results in
smaller compressed image. This only affects compression.
|Perform inter-block smoothing on uncompressed image. Only useful
for low-quality images. This only affects decompression.