Re: TIFF compression support list

On Thu, 28 Sep 2023, frechefuchs via Graphicsmagick-help wrote:

> With the following patch, the build completed.  And compression support
> list doesn't mention LZW anymore:
>
>> ./rungm.sh ./utilities/gm convert -list formats | grep -A1 " TIFF P"
>>      TIFF P  rw+  Tagged Image File Format (LIBTIFF, Version 4.1.0)
>>             Supported Compressions: None, Fax/Group3, Group4, JBIG, JPEG, LZMA, RLE, ZIP, ZSTD, WEBP
>
> Still WEBP compression support is indicated, even though libwebp-dev is
> not installed.

If it is not clear, when libtiff is compiled, it supports a certain 
set of codecs.  You are using an Ubuntu-provided libtiff and so 
someone else compiled it for you.  The -dev package allows compiling 
and linking against the Ubuntu-provided libtiff.

You can convince GM to support a subset of the codecs that libtiff 
supports.  Perhaps there should be an easier way to do this.

Bob
-- 
Bob Friesenhahn
[email protected], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
Public Key,     http://www.simplesystems.org/users/bfriesen/public-key.txt