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53 lines
2.1 KiB
TeX
53 lines
2.1 KiB
TeX
\section{\module{rgbimg} ---
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Read and write ``SGI RGB'' files}
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\declaremodule{builtin}{rgbimg}
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\modulesynopsis{Read and write image files in ``SGI RGB'' format (the module
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is \emph{not} SGI specific though!).}
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The \module{rgbimg} module allows Python programs to access SGI imglib image
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files (also known as \file{.rgb} files). The module is far from
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complete, but is provided anyway since the functionality that there is
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enough in some cases. Currently, colormap files are not supported.
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\note{This module is only built by default for 32-bit platforms; it is
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not expected to work properly on other systems.}
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The module defines the following variables and functions:
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\begin{excdesc}{error}
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This exception is raised on all errors, such as unsupported file type, etc.
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\end{excdesc}
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\begin{funcdesc}{sizeofimage}{file}
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This function returns a tuple \code{(\var{x}, \var{y})} where
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\var{x} and \var{y} are the size of the image in pixels.
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Only 4 byte RGBA pixels, 3 byte RGB pixels, and 1 byte greyscale pixels
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are currently supported.
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\end{funcdesc}
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\begin{funcdesc}{longimagedata}{file}
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This function reads and decodes the image on the specified file, and
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returns it as a Python string. The string has 4 byte RGBA pixels.
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The bottom left pixel is the first in
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the string. This format is suitable to pass to \function{gl.lrectwrite()},
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for instance.
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\end{funcdesc}
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\begin{funcdesc}{longstoimage}{data, x, y, z, file}
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This function writes the RGBA data in \var{data} to image
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file \var{file}. \var{x} and \var{y} give the size of the image.
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\var{z} is 1 if the saved image should be 1 byte greyscale, 3 if the
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saved image should be 3 byte RGB data, or 4 if the saved images should
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be 4 byte RGBA data. The input data always contains 4 bytes per pixel.
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These are the formats returned by \function{gl.lrectread()}.
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\end{funcdesc}
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\begin{funcdesc}{ttob}{flag}
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This function sets a global flag which defines whether the scan lines
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of the image are read or written from bottom to top (flag is zero,
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compatible with SGI GL) or from top to bottom(flag is one,
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compatible with X). The default is zero.
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\end{funcdesc}
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