Transparent TIFF for InDesign

[nniico]

I need to convert an SVG drawing to a TIFF CMYK image for importing in InDesign. I'm using the following command line :

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convert -density 300 -background none chart.svg +profile icm -profile sRGB.icm -profile ISOuncoated.icc chart.tiff

When I open the generated TIFF in InDesign, the background is black, no transparency.

I tried to open the file in Photoshop, then save it again in TIFF: it loads perfectly in InDesign. I could not really see what is different between the 2 versions, except for the embedded profiles. Mine only have the selected ICC. The photoshop version has the following :

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    Profile-8bim: 6252 bytes
    Profile-icc: 1528264 bytes
      ISO Uncoated
    Profile-tiff:37724: 100944 bytes
    Profile-xmp: 14548 bytes

Also, I get the following error when using the convert tool on this image:

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identify:chart-psd.tiff: unknown field with tag 37724 (0x935c) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/704.

It seems that photoshop is embedding something else (path or channel?).

How do I get the same kind of image with ImageMagick?

[fmw42]

PSD and TIFF files created in Photoshop or similar tools have special background transparency (in addition to alpha channel transparency) that is not supported by other imaging tools that can only support one kind of transparency. Those tools, like IM, convert the background transparency to an alpha channel, which you can still find in Photoshop. It is just the display in PS that then will not see the original background transparency as it has been converted to an alpha channel.

The tiff warning is just a warning that it does not know about some particular tiff information field. It does not affect the processing of the image.