Legacy ImageMagick Discussions Archive

I've use ImageMagick to convert/compress 100k images and haven't seen this before.

>> What is unique with this image?

>> Is there something else I need to support transparency in the pallet?
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Here's the original logo (png): (1.84 KB)

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Here's what happens when I compress with -pallet: (699 bytes)

magick.exe 179588.png -colors 256 -quality 90 -depth 8 -define png:compression-level=9 -define png:compression-filter=0 -define png:compression-strategy=0 -type palette -strip 179588_compressed_with_pallet.png
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Here's what happens when I compress without -pallet: (2.08 KB)

magick.exe 179588.png -colors 256 -quality 90 -depth 8 -define png:compression-level=9 -define png:compression-filter=0 -define png:compression-strategy=0 -strip 179588_No_Pallet.png
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More information:

• "-type pallet" seems to be what causes all the problems.

• PhotoShop can read the file and the problem still occurs when I resave from PhotoShop.

• The image does have a transparent background.

• TinyPng compresses it correctly with no loss.

You say:

QpgDev wrote:"-type pallet" seems to be what causes all the problems.

What problem? That transparency (alpha) isn't saved? The "palette" type doesn't save alpha.

But "-type PaletteAlpha" does.