Questions and postings pertaining to the usage of ImageMagick regardless of the interface. This includes the command-line utilities, as well as the C and C++ APIs. Usage questions are like "How do I use ImageMagick to create drop shadows?".
I have a number of TIF files with a compression tag of 34712 (JPEG2000). These images show up completely black in the majority of viewers.
I'm trying to convert these to any other format but get the error: Compression scheme 34712 scanline decoding is not implemented.
Does anyone know how I can convert these files? Is it possible to change the container without trying to decompress the image?
I do not know if Imagemagick via libtiff supports JPG2000 compression. You would have to check with the libtiff software to see. Imagemagick uses libtiff to read TIFF files and decompress them. Also see this other post viewtopic.php?f=1&t=16800
I don't think that libtiff directly supports JPEG2000 compression.
Can you point me to a sample file, or some format documentation?
I'd guess that a single-strip TIFF/JPEG2000 image like yours simply contains an embedded "JPEG 2000 codestream". If so, it should have the byte pattern 0xFF 0x4F 0xFF at offset 1770 (per the StripOffset). If you make a copy of your file, delete the first 1770 bytes, and give it a .j2c extension, it should be readable by JPEG2000 software. You would lose any metadata or other information contained only in the TIFF wrapper, though.
To clarify my libtiff comment, I mean that libtiff does not have an option to compile in JPEG2000 compression support. An app like ImageMagick could presumably implement its own JPEG2000 codec, and register it with libtiff at runtime. But the current version of IM does not appear to ever do that.
