Picture looks different in different software and online

[cuivenion]

Here's an odd one. I recently imaged M13, stacked in DSS, processed in DSS and Registax, then added some finishing touches in Gimp. I exported the finished file to PNG in Gimp and opened it up in Windows Photo viewer and it looked fine. I uploaded it and the image looked like it did before the Gimp processing. The mode is set to sRGB so the colour profile should be fine.

When I reopen the same file in Gimp I get the same result, the processing is gone! But Windows Photo Viewer shows the processing. I'm very confused

[cuivenion]

The picture was taken with a webcam and the the original files were 8 bit PNGs. DSS saved as a 16 bit TIF and so did Registax.

I've just realised that gimp is 8 bit only, could this be the problem? Any help would be very appreciated.

[NigeB]

Hi Cuivenion,

I had similar issues when I uploaded (non-astro) images to Flickr - I found the colours were different (dull, lacking saturation) in the online version. In my case, it turned out to be a problem with the way the colorspace was being interpreted by the browser. I found that my online images looked quite different depending on whether I used IE, Firefox or Chrome. I also found that if I downloaded the dull looking version of the image from the web, and displayed it locally, the colours were back to normal.

It might help to try the same thing with your images, to narrow down the possibilities. For info, there are some useful discussions here - you might not be using Flickr, and I can see you've already thought about colorspace, but some of this may still be useful.

 

https://www.flickr.com/help/forum/en-us/72157651011933755/
https://www.flickr.com/groups/775357@N23/discuss/72157631769810226/http://jiwhite.blogspot.co.uk/2005/10/resolving-flickr-color-saturation-loss.html

 

Nigel

 

 

[SonnyE]

You might be confused... But I am dumbfounded.

I have yet to have any successes with trying to stack anything.

One friend told me that I do my stacking with time in a single exposure.

One day recently I managed to get a few exposures to go through the gyrations. But alas, the resulting image more resembled something in the toilet after consuming too much alcohol.

That's probably why my delete key is so worn....

[cuivenion]

Hi Just seen these replies. Thanks for the info NigeB. SonnyE if you are using DeepSkyStacker you need to align the colours when the stack is done, otherwise the image will look terrible. You can do this in DSS or another processing program. Have a look at this thread:

https://stargazerslounge.com/topic/74690-rgb-align-in-dss/

[cuivenion]

For future reference I've managed to solve the problem and the images all look the same in all my image viewing software. This is the Gimp workflow I used.

Gimp Workflow:

1. Open Image.
2. Image>Mode>Convert to color profile
3. Convert to RGB Workspace (sRGB Built in)
4. Process image.
5. Export image as PNG , 0 Compression Level, Only save Creation time and resolution.

[cuivenion]

Nope, back to not working again as before. I really am baffled.