问题
I have been trying to run the following script on ImageMagick on a Linux server
convert resized.png -gravity Center -crop 1024X768+0+0 +repage flower.png
but have been hitting the following error:
convert: no decode delegate for this image format `PNG' @ error/constitute.c/ReadImage/501.
convert: no images defined `flower.png' @ error/convert.c/ConvertImageCommand/3212.
It looks like there is no delegate for PNG.
When I run:
identify -version
I get this result that shows that the PNG delegate is not installed:
Version: ImageMagick 6.9.0-4 Q16 x86_64 2015-01-25 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2015 ImageMagick Studio LLC
Features: DPC OpenMP
Delegates (built-in): bzlib freetype jpeg lcms tiff x zlib
As far as I can tell I have 'libpng' installed on my server.
How do I configure the PNG delegate for ImageMagick on my Linux server?
I have 'yum' installed but not 'apt-get'.
回答1:
I did a lot more searching and found this answer.
It looks like ImageMagick did not know what library to look for.
I did a
locate libpng
and found that it was located in
/usr/lib64/
I was then able to run the commands on this page (from within the ImageMagick directory):
http://www.imagemagick.org/discourse-server/viewtopic.php?t=12366
./configure --enable-shared
make libdir=/usr/lib64
make libdir=/usr/lib64 install
./configure --enable-shared=yes --x-libraries=/usr/lib64 --without-perl
make
make install
Then running
identify -version
showed the following results:
Version: ImageMagick 6.9.0-4 Q16 x86_64 2015-01-30
http://www.imagemagick.org
Copyright: Copyright (C) 1999-2015 ImageMagick Studio LLC
Features: DPC OpenMP
Delegates (built-in): bzlib freetype jng jpeg lcms png tiff x zlib
which shows that PNG is now installed as a delegate.
来源：https://stackoverflow.com/questions/28237800/configuring-png-on-imagemagick-on-a-linux-server