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1 |
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2 :mod:`imgfile` --- Support for SGI imglib files |
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3 =============================================== |
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4 |
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5 .. module:: imgfile |
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6 :platform: IRIX |
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7 :synopsis: Support for SGI imglib files. |
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8 :deprecated: |
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9 |
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10 .. deprecated:: 2.6 |
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11 The :mod:`imgfile` module has been deprecated for removal in Python 3.0. |
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12 |
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13 |
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14 |
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15 The :mod:`imgfile` module allows Python programs to access SGI imglib image |
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16 files (also known as :file:`.rgb` files). The module is far from complete, but |
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17 is provided anyway since the functionality that there is enough in some cases. |
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18 Currently, colormap files are not supported. |
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19 |
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20 The module defines the following variables and functions: |
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21 |
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22 |
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23 .. exception:: error |
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24 |
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25 This exception is raised on all errors, such as unsupported file type, etc. |
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26 |
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27 |
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28 .. function:: getsizes(file) |
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29 |
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30 This function returns a tuple ``(x, y, z)`` where *x* and *y* are the size of |
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31 the image in pixels and *z* is the number of bytes per pixel. Only 3 byte RGB |
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32 pixels and 1 byte greyscale pixels are currently supported. |
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33 |
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34 |
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35 .. function:: read(file) |
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36 |
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37 This function reads and decodes the image on the specified file, and returns it |
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38 as a Python string. The string has either 1 byte greyscale pixels or 4 byte RGBA |
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39 pixels. The bottom left pixel is the first in the string. This format is |
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40 suitable to pass to :func:`gl.lrectwrite`, for instance. |
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41 |
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42 |
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43 .. function:: readscaled(file, x, y, filter[, blur]) |
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44 |
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45 This function is identical to read but it returns an image that is scaled to the |
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46 given *x* and *y* sizes. If the *filter* and *blur* parameters are omitted |
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47 scaling is done by simply dropping or duplicating pixels, so the result will be |
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48 less than perfect, especially for computer-generated images. |
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49 |
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50 Alternatively, you can specify a filter to use to smooth the image after |
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51 scaling. The filter forms supported are ``'impulse'``, ``'box'``, |
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52 ``'triangle'``, ``'quadratic'`` and ``'gaussian'``. If a filter is specified |
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53 *blur* is an optional parameter specifying the blurriness of the filter. It |
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54 defaults to ``1.0``. |
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55 |
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56 :func:`readscaled` makes no attempt to keep the aspect ratio correct, so that is |
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57 the users' responsibility. |
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58 |
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59 |
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60 .. function:: ttob(flag) |
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61 |
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62 This function sets a global flag which defines whether the scan lines of the |
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63 image are read or written from bottom to top (flag is zero, compatible with SGI |
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64 GL) or from top to bottom(flag is one, compatible with X). The default is zero. |
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65 |
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66 |
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67 .. function:: write(file, data, x, y, z) |
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68 |
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69 This function writes the RGB or greyscale data in *data* to image file *file*. |
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70 *x* and *y* give the size of the image, *z* is 1 for 1 byte greyscale images or |
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71 3 for RGB images (which are stored as 4 byte values of which only the lower |
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72 three bytes are used). These are the formats returned by :func:`gl.lrectread`. |
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73 |