[horde] problem with convert in ansel

[Uttiya Chowdhury]

Hi all, 
my ansel (git) is failing to display any images in thumbnail, or slide show. But if I download the image file, it downloads fine. Looking at the horde logfile, the problem seems to be with convert (log file excerpt attached). Any thoughts? 

BTW, the machine is a gentoo server with probably a minimal set of USE features, so it is not unlikely that some required USE were not included when building convert. But any guidance on what I need will be greatly appreciated.

Thanks.

UC

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convert: no decode delegate for this image format `/tmp/imgewv9xg' @ error/constitute.c/ReadImage/544.
convert: no images defined `png:/tmp/imgKts62M' @ error/convert.c/ConvertImageCommand/3044. [pid 6111 on line 1164 of "/mnt/ce/main/Open/0.Admin/ansel/lib/Image.php"]
2013-03-13T15:41:40+08:00 ERR: HORDE [ansel] Error running command: /usr/bin/convert -size 0x0 xc:white +profile "*" png:"/tmp/imgy4ZKsk" 2>&1
convert: no encode delegate for this image format 'png:/tmp/imgy4ZKsk' @ error/constitute.c/WriteImage/1212. [pid 6111 on line 441 of "/mnt/ce/main/Open/0.Admin
/libs/Horde/Image/Base.php"]
2013-03-13T15:41:40+08:00 ERR: HORDE [ansel] Error running command: /usr/bin/convert -size 1600x1178 "/tmp/imgKCA8xp"'[0]' -thumbnail 800x589 +profile "*" jpeg:
"/tmp/imgmAHX5W" 2>&1
convert: no decode delegate for this image format `/tmp/imgKCA8xp' @ error/constitute.c/ReadImage/544.
convert: no images defined `jpeg:/tmp/imgmAHX5W' @ error/convert.c/ConvertImageCommand/3044. [pid 6111 on line 441 of "/mnt/ce/main/Open/0.Admin/libs/Horde/Image/Base.php"]
2013-03-13T15:41:40+08:00 EMERG: HORDE [ansel] Error running command: /usr/bin/convert -size 1600x1178 "/tmp/imgKCA8xp"'[0]' -thumbnail 800x589 +profile "*" jpeg:"/tmp/imgmAHX5W" 2>&1
convert: no decode delegate for this image format `/tmp/imgKCA8xp' @ error/constitute.c/ReadImage/544.
===