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Guido van Rossum5fdeeea1994-01-02 01:22:07 +00001\section{Built-in module \sectcode{rgbimg}}
2\bimodindex{rgbimg}
3
4The rgbimg module allows python programs to access SGI imglib image
5files (also known as \file{.rgb} files). The module is far from
6complete, but is provided anyway since the functionality that there is
7is enough in some cases. Currently, colormap files are not supported.
8
9The module defines the following variables and functions:
10
11\renewcommand{\indexsubitem}{(in module rgbimg)}
12\begin{excdesc}{error}
13This exception is raised on all errors, such as unsupported file type, etc.
14\end{excdesc}
15
16\begin{funcdesc}{sizeofimage}{file}
17This function returns a tuple \code{(\var{x}, \var{y})} where
18\var{x} and \var{y} are the size of the image in pixels.
19Only 4 byte RGBA pixels, 3 byte RGB pixels, and 1 byte greyscale pixels
20are currently supported.
21\end{funcdesc}
22
23\begin{funcdesc}{longimagedata}{file}
24This function reads and decodes the image on the specified file, and
25returns it as a python string. The string has 4 byte RGBA pixels.
26The bottom left pixel is the first in
27the string. This format is suitable to pass to \code{gl.lrectwrite},
28for instance.
29\end{funcdesc}
30
31\begin{funcdesc}{longstoimage}{data\, x\, y\, z\, file}
32This function writes the RGBA data in \var{data} to image
33file \var{file}. \var{x} and \var{y} give the size of the image.
34\var{z} is 1 if the saved image should be 1 byte greyscale, 3 if the
35saved image should be 3 byte RGB data, or 4 if the saved images should
36be 4 byte RGBA data. The input data always contains 4 bytes per pixel.
37These are the formats returned by \code{gl.lrectread}.
38\end{funcdesc}
39
40\begin{funcdesc}{ttob}{flag}
41This function sets a global flag which defines whether the scan lines
42of the image are read or written from bottom to top (flag is zero,
43compatible with SGI GL) or from top to bottom(flag is one,
44compatible with X). The default is zero.
45\end{funcdesc}