Legacy ImageMagick Discussions Archive

Hello,
I have a problem converting CR2 files (canon Raw image formats). The converted image appears almost completely dark (as if grossely underexposed like a -2 or -3 even compared to the conversion shield by the canon software without any modifications)

IM Version: WIN 6.6.1-2-Q16 (executable installer)
OS: Win XP

I have tryed with: Shade (Off/On) - depth (8/16) - colorspace (sRGB ... at least this is what the camera says is using). All gives the same result...

As soon as I figure out how to put an image here I'll show examples

Many thanks in advance for any hint and Thanks to the developers for a great work!!

regards
Alejandro

Its a problem something to do with DCRAW changing?
There is a way around it but IM looks for the wrong temporary image name and IM is not going to be modified to sort the problem.
viewtopic.php?f=1&t=15605&p=55544#p55544

ImageMagick creates a linear colorspace by default and expects you to apply your own color corrections. To do this automatically, change -4 to -6 for the dng:decode delegate in the delegates.xml ImageMagick configuration file. Now convert your image again.

Thanks for the replies!

magick wrote:ImageMagick creates a linear colorspace by default and expects you to apply your own color corrections. To do this automatically, change -4 to -6 for the dng:decode delegate in the delegates.xml ImageMagick configuration file. Now convert your image again.

This corrected the problem. Works like a charm. Thanks again!

regards
Alejandro

What does -4 and -6 mean ?
In my case -4 is underexposed and -6 is overexposed; -5 would probably be just right but it does not work.

But saying that the sky from -4 on the -6 image would be great!

Hi Bonzo,
Just type "dcraw" as a command in a DOS box and it will list all the program's optional arguments. The one you need is probably the -w option.

Pete

Thanks for the tip Pete.

The standard line I have in the delegates file is: This produced the first image posted; taking the -w out I ended up with an image tinted orange.

I then tried adding and removing the -W "Don't automaticaly brighten the image" but this had little effect.

I also had a play with -b and -s without success; I think in this sort of case its better to use a GUI program.

The reason I was originaly looking into this was for the "dead pixel" removal and I see that dcraw has an option for that -P which I will look into when I get a bit more time.