How to convert CR2 to JPG or PNG?

Question

I need to convert a lot of CR2 photos to either JPG or PNG, no editing. How to do this?

Answer 1

I'll go a different route... Use ufraw-batch not ufraw.

sudo apt-get install ufraw-batch

## This will output (not replace) the file with a new extension.
## foo.CR2 exported to foo.png
ufraw-batch --out-type png *.CR2

See ufraw-batch --help and man ufraw-batch for more info.

Answer 2

ufraw alternatives

The accepted answer recommends to use ufraw, but ufraw's development has ceased as of June 2015 and it's not supported by current Ubuntu releases. See Ubuntu Bugtracker, which recommends darktable or rawtherapee as alternatives. Both tools are GU tools, but it is possible to use them from CLI.

darktable: manual, man page

Batch processing example:

for pic in *.CR2
do
     darktable-cli "$pic" "$(basename ${pic%.CR2}.jpg)"; 
done

rawtherapee: manual

Answer 3

Ufraw

you can convert .cr2 to .jpeg by ufraw.

sudo apt-get install ufraw

Right click on the file and select open with ufraw.

** You can also import them to Gimp with gimp-ufraw and then export as .png or .jpeg.

sudo apt-get install gimp-ufraw

Answer 4

For another alternative, use mogrify:

mogrify -format png *.cr2

Answer 5

Try nconvert

As command line tool OR xnconvert as GUI tool

Answer 6

The method that really worked for me:

You need dcraw and ppmtojpeg (install with apt)

for i in *.CR2; do dcraw -c $i | ppmtojpeg > $1.jpg; echo $i done; done

What it does: First convert CR2 to PPM with dcraw passing the output to ppmtojpeg which converts to JPG.

I found this here

Answer 7

Create a bash file like foo.sh and execute as ./foo.sh in command line:

#!/bin/sh

for i in $(ls)
do
ufraw-batch --out-type png $i
echo "conversion done $i"
done

Answer 8

I had trouble with ufraw since it produces a segmentation fault on elementary OS (see https://bugs.launchpad.net/ubuntu/+source/ufraw/+bug/1768855). I combined your answers (thanks!) and finally got a working version.

First get the right command for exiftool (as mentioned by Rafael):

exiftool -s2 -all -b -X -fXMP:XMP test.RAF  | grep Preview

which is in my case not -Composite:PreviewImage but:

File:PreviewImage

So you can use the batch script from Abu:

#!/bin/sh

for i in *.RAF
do
exiftool -File:PreviewImage -b $i > $i.jpg
echo $i
done

Answer 9

You could also program a simple loop in the console.

For example (using the fish console), and assuming the active directory only has RAW files.

set files (ls)
for i in $files
    dcraw $i
end

or

set files (ls)
for i in $files
    ufraw-batch --out-type=tif --out-depth $i
end

I use ufraw-batch that way because it often leads to an error, see https://bugs.launchpad.net/ubuntu/+source/ufraw/+bug/1768855 .

Answer 10

Use:

exiftool -Composite:PreviewImage -b photo.CR2 > photo.jpg

Longer answer:

ufraw-batch conversion quality is very bad. Imagemagick uses ufraw under the hoods (unfortunately). dcraw is better, but still not great. The best solution I found out was to use exif to extract PreviewImage metadata. I believe that's generated by the camera itself.

Ref: https://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=6936&sid=9548c421f1bd69f192e632d06ca03dff&start=30#p130949