Deprecated since version 2.6: The
jpeg module has been removed in Python 3.
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/.
jpeg module defines an exception and some functions.
compress(data, w, h, b)¶
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 format.
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
Force output to be grayscale, even if input is RGB.
Set the quality of the compressed image to a value between
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.
- JPEG Still Image Data Compression Standard
- The canonical reference for the JPEG image format, by Pennebaker and Mitchell.
- Information Technology - Digital Compression and Coding of Continuous-tone Still Images - Requirements and Guidelines
- The ISO standard for JPEG is also published as ITU T.81. This is available online in PDF form.