Guido van Rossum | 5fdeeea | 1994-01-02 01:22:07 +0000 | [diff] [blame] | 1 | \section{Built-in module \sectcode{rgbimg}} |
| 2 | \bimodindex{rgbimg} |
| 3 | |
| 4 | The rgbimg module allows python programs to access SGI imglib image |
| 5 | files (also known as \file{.rgb} files). The module is far from |
| 6 | complete, but is provided anyway since the functionality that there is |
| 7 | is enough in some cases. Currently, colormap files are not supported. |
| 8 | |
| 9 | The module defines the following variables and functions: |
| 10 | |
| 11 | \renewcommand{\indexsubitem}{(in module rgbimg)} |
| 12 | \begin{excdesc}{error} |
| 13 | This exception is raised on all errors, such as unsupported file type, etc. |
| 14 | \end{excdesc} |
| 15 | |
| 16 | \begin{funcdesc}{sizeofimage}{file} |
| 17 | This function returns a tuple \code{(\var{x}, \var{y})} where |
| 18 | \var{x} and \var{y} are the size of the image in pixels. |
| 19 | Only 4 byte RGBA pixels, 3 byte RGB pixels, and 1 byte greyscale pixels |
| 20 | are currently supported. |
| 21 | \end{funcdesc} |
| 22 | |
| 23 | \begin{funcdesc}{longimagedata}{file} |
| 24 | This function reads and decodes the image on the specified file, and |
| 25 | returns it as a python string. The string has 4 byte RGBA pixels. |
| 26 | The bottom left pixel is the first in |
| 27 | the string. This format is suitable to pass to \code{gl.lrectwrite}, |
| 28 | for instance. |
| 29 | \end{funcdesc} |
| 30 | |
| 31 | \begin{funcdesc}{longstoimage}{data\, x\, y\, z\, file} |
| 32 | This function writes the RGBA data in \var{data} to image |
| 33 | file \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 |
| 35 | saved image should be 3 byte RGB data, or 4 if the saved images should |
| 36 | be 4 byte RGBA data. The input data always contains 4 bytes per pixel. |
| 37 | These are the formats returned by \code{gl.lrectread}. |
| 38 | \end{funcdesc} |
| 39 | |
| 40 | \begin{funcdesc}{ttob}{flag} |
| 41 | This function sets a global flag which defines whether the scan lines |
| 42 | of the image are read or written from bottom to top (flag is zero, |
| 43 | compatible with SGI GL) or from top to bottom(flag is one, |
| 44 | compatible with X). The default is zero. |
| 45 | \end{funcdesc} |