I am generating thumbnails and medium sized images from large photos. These smaller photos are for display in an online gallery. Many of the photographers are submitting JPEG images using Adobe RGB. I have been asked if the thumbnail and medium size images can use sRGB as the images as is appear "flat" in some browsers.
I'm currently using ImageMagick to create the smaller versions. It has a -colorspace option, but that doesn't seem to do what I want.
Is there any other way to do this? Also, do you think this is worthwhile?
You can use the ImageMagic -profile option:
convert image.jpg -profile <adobe.icc> -profile <sRGB.icc> new_image.jpg
See here for more details:
http://www.imagemagick.org/Usage/formats/#color_profile.
Have you tried using Little CMS? This command will convert an image with a special color profile (i.e. Adobe RGB 1998) to one with no color profile but the same effective colors:
jpgicc -q100 input.jpg output.jpg
I'm setting JPEG quality to 100 here.
The following thread in the ImageMagick forum discusses exactly this in some detail: http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=16464
I now use this bash script to convert any picture (including CMYK) to sRGB:
http://alma.ch/scripts/any2srgb
It requires icc profiles for images which don't have embedded profiles. These can be found easily on the web. For example on Adobe's site: http://www.adobe.com/cfusion/search/index.cfm?term=icc+profile&siteSection=support%3Adownloads
Here is a summary (untested) of what the full script does (without it's resize and other options). It requires profiles and ImageMagick. On Debian-based systems: apt-get install icc-profiles imagemagick.
#!/bin/bash
srgb=sRGB.icm
cmyk=ISOwebcoated.icc
# extract possible color profile
profile="${f/%.*/.icc}"
convert "$f" "icc:$profile" 2>/dev/null
if cmp -s "$profile" "$srgb" ; then
# embedded profile is already srgb. Nothing to do
exit
fi
if [ -s "$profile" ]; then
# we have an embedded profile, so ImageMagick will use that anyway
convert "$f" -profile "$srgb" +profile '*' "$outfile"
else
# no embedded profile in source
if identify -format "%r" "$f" | grep -q CMYK; then
# CMYK file without embedded profile
convert "$f" -profile "$cmyk" -profile "$srgb" "$outfile"
fi
fi
Re-exporting the image using Krita seems to work well enough for me:
krita my_img.jpg --export --export-filename my_img_in_srgb.jpg
Krita is an open source Photoshop/Paint, with a(n extremely limited) command line interface. Install it with
sudo apt install krita
Related
I have a DNG image and a cropped monochromatic version of the image. Both are generating the same file as the thumbnail when I run any of the below commands:
magick.exe C:\sample1crop.dng -resize 500x375 C:\crop-T.JPG
or
magick.exe dng:C:\sample1crop.dng -intent relative -sample 500x375> -strip -auto-orient -density 72 C:\crop-T.JPG
or
magick.exe convert dng:C:\sample1original.dng -thumbnail 500x375 -filter -auto-orient -density 72 C:\orig-T.JPG
As I am not allowed to upload the DNG files, thus I uploaded the images in hightail, sharing the link below: https://spaces.hightail.com/space/ThDEDYZVey
The generated thumbnail for both the cases:
I tried to get the thumbnail with exiftool as well:
exiftool -b -PreviewImage C:\86854\SLS\Issues\ART-73712\crop-T.JPG > C:\86854\SLS\Issues\ART-73712\thumbnail.jpg
exiftool -b -ThumbnailImage C:\86854\SLS\Issues\ART-73712\crop-T.JPG > C:\86854\SLS\Issues\ART-73712\thumbnail.jpg
but the resulting file seems corrupted. When I extract the exiftool metadata I see:
"ThumbnailTIFF": "(Binary data 42194 bytes, use -b option to extract)"
My requirement here is to get a generic cmd that provides a cropped monochromatic thumbnail similar to the original image.
Using this exiftool command, I was able to extract four images from those files.
You don't mention what OS or shell you're using but if you're using Windows PowerShell, it is known to corrupt binary data when piping or redirecting. Use CMD and you should be able to extract the images properly.
I tried to resize a very big image (457 MB and 21600x21600) with the following command
-i test.png -vf scale=320:-1 out.png
but it throws exception saying "Picture size 21600x21600 is invalid". How can I find out the biggest supported resolution by ffmpeg? Is there a way to resize this high resolution image with ffmpeg?
If you want to use ImageMagick it is included in most Linux distros and is available for macOS and Windows.
Your command becomes:
convert test.png -resize 320x result.png
If you are running v7 or newer, use:
magick test.png -resize 320x result.png
If you have lots to do, and you want all the resized images written in a directory called thumbs you can use:
mkdir thumbs
magick mogrify -path thumbs -resize 320x *.png
Alternatively, you may find vips is a lighter-weight installation and does a faster conversion using less memory:
mkdir thumbs
vipsthumbnail -s 320 -o "thumbs/%s.png" image.png
I am on CentOS 6.4 and trying to convert .CDR to .SVG Convert Using ImageMagick using SSH command.
my 1.cdr file is in /var/www/vhosts/website.com/httpdocs/test/1.cdr
once converted to SVG it should be created in the same folder
Tried the following command:
convert /var/www/vhosts/website.com/httpdocs/test/1.cdr image.svg
The Error I am getting is:
sh: mplayer: command not found convert: Delegate failed "mplayer"
"%i" -really-quiet -ao null -vo png:z=3' #
delegate.c/InvokeDelegate/1032. convert: missing an image filename
image.svg' # convert.c/ConvertImageCommand/2800.
Not sure what does that mean ?
In order to convert CDR files you need to install uniconvertor for CDR delegate.
List of all delegates:
convert -list delegate
By default it outputs:
cdr => "uniconvertor" "%i" "%o.svg"; mv "%o.svg" "%o"
Install uniconvertor. For example, on Ubuntu it’s:
sudo apt-get install python-uniconvertor
Then run:
convert image.cdr -flatten -thumbnail '512x512' image.png
Or, with zoom cropping:
convert image.cdr -flatten -thumbnail '512x512^' -gravity center -crop 512x512+0+0 +repage image.png
And you’re done.
I convert to PNG here but you may use your own output format.
python-uniconvertor is part of inkscape.
It does not exist by itself.
Ubuntu/Mint recently removed all the old Python stuff, for Corel Draw I have to fire up the WinXP VM & Corel and export something Linux understands, usually PNG, a favourite
CDR & WMF files are pretty much dead to Linux, ImageMagick can still handle WMF though.
Download latest version of ImageMagick. Unpacked it. Installing Ghostscript like this:
$ sudo apt-get install ghostscript
After that try to configure ImageMagick:
$ ./configure --with-gslib
$ make
$ make install
After that i try to conver PDF to jpg
$ sudo /usr/local/bin/convert in.pdf out.jpg
And i see this mistake
convert: no decode delegate for this image format `/tmp/magick-BzHdr4Kp-00000001' # error/constitute.c/ReadImage/544.
convert: Postscript delegate failed `in.PDF': Нет такого файла или каталога # error/pdf.c/ReadPDFImage/678.
convert: no images defined `out.jpg' # error/convert.c/ConvertImageCommand/3044.
What i'm doing wrong?
Try the following convert commands to see more precisely what's possibly going wrong:
convert a.pdf -debug coder a.jpg
convert a.pdf -debug all a.jpg
There will possibly be a lot of output going to stderr. Amongst the lines you may see where IM is looking for Ghostscript. Also, try
convert -list delegate
convert -list delegate | grep --color -E '(eps|pdf)'
to find with which exact commandlines ImageMagick tries to run Ghostscript (it may call gsx instead of gs, or it may look for it in /usr/local/bin/...). If you find any deviations from your real Ghostscript installation, you can possibly fix it by editing delegates.xml.
convert -list configure
will show you how ImageMagick is configured (and if, for example, gs was during compile-time in the list in DELEGATES variables). Here you also find where to look for delegates.xml:
convert -list configure | grep CONFIGURE_PATH
should list the directory where this (as well as some more) *.xml settings files are located which control how convert et al. behave...
How to convert a JPEG image into SVG format using ImageMagick?
you'll need to use potrace and convert to a bitmap first.
$convert input.jpg output.ppm
$potrace -s output.ppm -o svgout.svg
Actually, with a complete installation of a recent version of ImageMagick it should be as easy as:
convert some.jpeg some.svg
Of course, ImageMagick cannot do it all by itself -- it uses delegates (helper programs) to handle SVG input or output. (This has been pointed out by other answers already.)
To see a (partial) list of all delegates (and their respective commands), run
convert -list delegate
To see the config file where all the delegate secrets hide, see
convert -list delegate | grep delegates.xml
To see a (partial) list of SVG handling delegates, run
convert -list delegate | grep -i svg
However, ImageMagick likes to put some of its external helper utilities into 'stealth' mode and doesn't necessarily reveal their presence when using above commands.
Just look into the delegates.xml file itself. On my system it's:
grep -i svg /opt/local/etc/ImageMagick/delegates.xml | grep -i --color stealth
<delegate decode="autotrace" stealth="True" \
command=""/opt/local/bin/convert" "%i" \
"pnm:%u"\n\
"/opt/local/bin/autotrace" \
-input-format pnm \
-output-format svg \
-output-file "%o" "%u""/>
<delegate decode="svg:decode" stealth="True" \
command=""/opt/local/bin/inkscape" "%s" \
--export-png="%s" \
--export-dpi="%s" \
--export-background="%s" \
--export-background-opacity="%s" \
> "%s" 2>&1"/>
As you may see, on my system the ImageMagick installation automatically uses (amongst others)...
...inkscape to convert SVG to PNG;
...autotrace to convert PNM to SVG;
Of course, one could argue the benefits of rather using autotrace directly -- but that would require to manually convert the whatever-input-format to PNM first. So for this preliminary step you'd probably use ImageMagick anyway...
You'll actually need some software or code to vectorize your image in between, as jpg is a raster format, while SVG is a vector format. I don't think imagemagick alone can do that for you.