| \section{\module{rgbimg} --- |
| Read and write image files in ``SGI RGB'' format.} |
| \declaremodule{builtin}{rgbimg} |
| |
| \modulesynopsis{Read and write image files in ``SGI RGB'' format (the module is |
| \emph{not} SGI specific though!).} |
| |
| |
| The \module{rgbimg} module allows Python programs to access SGI imglib image |
| files (also known as \file{.rgb} files). The module is far from |
| complete, but is provided anyway since the functionality that there is |
| enough in some cases. Currently, colormap files are not supported. |
| |
| The module defines the following variables and functions: |
| |
| \begin{excdesc}{error} |
| This exception is raised on all errors, such as unsupported file type, etc. |
| \end{excdesc} |
| |
| \begin{funcdesc}{sizeofimage}{file} |
| This function returns a tuple \code{(\var{x}, \var{y})} where |
| \var{x} and \var{y} are the size of the image in pixels. |
| Only 4 byte RGBA pixels, 3 byte RGB pixels, and 1 byte greyscale pixels |
| are currently supported. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{longimagedata}{file} |
| This function reads and decodes the image on the specified file, and |
| returns it as a Python string. The string has 4 byte RGBA pixels. |
| The bottom left pixel is the first in |
| the string. This format is suitable to pass to \function{gl.lrectwrite()}, |
| for instance. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{longstoimage}{data, x, y, z, file} |
| This function writes the RGBA data in \var{data} to image |
| file \var{file}. \var{x} and \var{y} give the size of the image. |
| \var{z} is 1 if the saved image should be 1 byte greyscale, 3 if the |
| saved image should be 3 byte RGB data, or 4 if the saved images should |
| be 4 byte RGBA data. The input data always contains 4 bytes per pixel. |
| These are the formats returned by \function{gl.lrectread()}. |
| \end{funcdesc} |
| |
| \begin{funcdesc}{ttob}{flag} |
| This function sets a global flag which defines whether the scan lines |
| of the image are read or written from bottom to top (flag is zero, |
| compatible with SGI GL) or from top to bottom(flag is one, |
| compatible with X). The default is zero. |
| \end{funcdesc} |