Raster transparency doesn't handle alpha channel

[qissue-bot]

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Author Name: Borys Jurgiel (Borys Jurgiel)
Original Redmine Issue: 2491, https://issues.qgis.org/issues/2491

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Open a [[GeoTIFF]] with the aplha channel. No transparency occurs. In the layer properities all 4 channels are available for the color composition, but the 'transparency channel' combobox on the Transparency tab is disabled.

[qissue-bot]

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Original Redmine Comment
Author Name: Alister Hood (Alister Hood)
Original Date: 2011-08-10T22:17:26.000Z

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The same problem occurs for grayscale images with an alpha channel, and in Windows. An example image is attached at qgis#4159.

[qissue-bot]

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Original Redmine Comment
Author Name: Alister Hood (Alister Hood)
Original Date: 2011-10-04T20:08:06.000Z

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I remember some conjecture on the mailing list that this is simply a new feature which hasn't been implemented yet.
But apparently it was implemented even before the "pixel list" transparency by colour: #288-6

[qissue-bot]

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Original Redmine Comment
Author Name: Giuseppe Sucameli (Giuseppe Sucameli)
Original Date: 2011-10-19T03:37:36.000Z

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Here's the pull request: qgis#52

[qissue-bot]

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Original Redmine Comment
Author Name: Alexander Bruy (Alexander Bruy)
Original Date: 2011-10-27T09:19:11.000Z

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Applied in commit:b0112f1c42.