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<p class="MsoNormal"><span lang="EN-US">I’m trying to create gtiffs with transparent areas where there are voids between my original images.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">I have successfully done it by using an alpha band but this process created 3x larger images. I think partly because of an additional 4th band and partly because I cannot use ycbcr to compress with jpeg. So I thought
of using internal masks expecting to get smaller images but cannot get it to work.</span></p>
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<p class="MsoNormal"><span lang="EN-US">When converting from the rgba image using -mask 4 I cannot “see” the transparency and get black areas:</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">gdal_translate -b 1 -b 2 -b 3 -ma sk 4 --config GDAL_TIFF_INTERNAL_MASK YES test_alpha.tif test_internalmask.tif</span></p>
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<p class="MsoNormal"><span lang="EN-US">I tried looking at the images using qgis and paint.net.</span></p>
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<p class="MsoNormal"><span lang="EN-US">Any hints or help appreciated.</span></p>
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<p class="MsoNormal"><span lang="EN-US">Thanks,</span></p>
<p class="MsoNormal"><span lang="EN-US">Duarte</span></p>
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<strong>Duarte Carreira</strong><br>
Diretor | Dep. Informação Geográfica e Cartografia<br>
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