label: with partially transparent background
Posted: 2015-06-26T13:00:26-07:00
The label: pseudo-image doesn't seem to handle working with transparent backgrounds.
ImageMagick-6.9.1-Q16 64-bit on Windows 7
results in
I had to use -depth 8 as convert was giving a 64-bit RGBA (16-bit per channel) PNG without it. After adding the -depth 8, I found that the result must have been expressible as an PLTE+tRNS PNG, as that's what I initially got, so I added the png32: format specifier. If I understand correctly how png:32 works, then that's all I actually need and can skip the -depth 8, but I wanted to show exactly what I used to generate the above image.
As you can see, the transparency is wrong inside the letters. Work-arounds are welcome, but this probably needs fixed within the label: pseudo-image operation. Fully transparent works as expected (like #00CC0000), so I could probably compose that over a separately generated transparent background.
ImageMagick-6.9.1-Q16 64-bit on Windows 7
Code: Select all
convert -depth 8 -background #00CC0033 -pointsize 72 label:"This is a label" png32:label.pngI had to use -depth 8 as convert was giving a 64-bit RGBA (16-bit per channel) PNG without it. After adding the -depth 8, I found that the result must have been expressible as an PLTE+tRNS PNG, as that's what I initially got, so I added the png32: format specifier. If I understand correctly how png:32 works, then that's all I actually need and can skip the -depth 8, but I wanted to show exactly what I used to generate the above image.
As you can see, the transparency is wrong inside the letters. Work-arounds are welcome, but this probably needs fixed within the label: pseudo-image operation. Fully transparent works as expected (like #00CC0000), so I could probably compose that over a separately generated transparent background.