How to save images with an embedded sRGB profile?

[georgian82]

Hi all,

I am having trouble when uploading my images to Astrobin as they show very differently from my PixInsight desktop (using the same computer). The colors don't match...

Salvatore Iovene from Astrobin suggested saving the images with an embedded sRGB profile prior to uploading them in Astrobin. How do I do that?

Thanks!
Sebastian

[pfile]

on the contrary i find that omitting the sRGB profile is the way to go with astrobin. IMO something is wrong on their end.

before saving your image as a jpg, use the ICCProfileTransformation process to convert your image to the sRGB color space. you can play around with the black point compensation and different modes to see which you like best. don't forget to remove any masks from your image before applying ICCProfileTransformation, as it is actually changing the values of the pixels to conform to the color space you choose.

then save the image with no profile attached, and upload that. it should be correct. in answer to your original question, when saving as JPG there is a check box that lets you attach a color profile - leave that unchecked.

rob

[georgian82]

on the contrary i find that omitting the sRGB profile is the way to go with astrobin. IMO something is wrong on their end.

before saving your image as a jpg, use the ICCProfileTransformation process to convert your image to the sRGB color space. you can play around with the black point compensation and different modes to see which you like best. don't forget to remove any masks from your image before applying ICCProfileTransformation, as it is actually changing the values of the pixels to conform to the color space you choose.

then save the image with no profile attached, and upload that. it should be correct. in answer to your original question, when saving as JPG there is a check box that lets you attach a color profile - leave that unchecked.

Rob,

Thank you so much for the help. I will give your suggestions a try tonight.

Cheers,
Sebastian

rob

[RickS]

on the contrary i find that omitting the sRGB profile is the way to go with astrobin. IMO something is wrong on their end.

Hi Rob, is that still the case?  For a long time Astrobin was stripping ICC Profiles but that eventually got fixed.  My impression was that it worked OK now apart from minor nits, e.g. when you mouse over the image you get a change in colour between the original image and the annotated version (plate solver strips the ICC profile.)

Mostly I upload images with an embedded AdobeRGB profile these days.  They look OK to me.  Not sure about anybody else

Cheers,
Rick.

[pfile]

oh, i didn't know it got fixed. i interpreted the mouseover problem you're describing as continued evidence that it was not fixed... meaning the platesolved image had a bogus ICC.

i guess you can do one of those crazy things like invert the image and then attach a profile that un-inverts it to prove that astrobin is really working right these days, but that's too much hassle

rob

[RickS]

It's never going to be a perfect world when it comes to colour management, but I think that Astrobin is now doing what they can.

Cheers,
Rick.

[georgian82]

Thank you all for the replies.

I have one more question...should I set the ICC tool before I begin working on my post processing or after I am done and just before I save to JPG?

Thanks again,

[pfile]

i would do it last. the sRGB profile is very restricted in what colors it can represent...

rob

[RickS]

Hi Sebastian,

Are you calibrating your monitor?  Do the images look the same in PI and when displayed in other (preferably colour managed apps?)

Here's a useful link that will check if your browser supports colour management: http://www.color.org/version4html.xalter and here's a jpg file that you can use to check whether an image display application is doing colour management: http://petapixel.com/assets/uploads/2012/06/S2fzq.jpg (if the car is purple then colour management is not working.)

Unfortunately, colour management requires a chain of things all working perfectly.  One failure and you're out of luck...

Cheers,
Rick.