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I've broken my exports as JPG somehow - Printable Version

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I've broken my exports as JPG somehow - andrewnewby - 03-18-2023

Hi,

I was playing around with my settings, as I always want JPG's to export at 100% quality (it always seems to want to downgrade to 90%?). Anyway - now when I export an image as a .jpg I get a corrupted image. Here is my settings:

https://ibb.co/bJht60W

(sorry, I don't seem to be able to embed images via , and the upload attachment doesn't seem to work?)

Anyhow - if I look at the generated .jpg file in Notepad++, I can see it has the right start:

ÿØÿà JFIF

So I'm unsure whats going on :/ When I try and open it in Photos I get:

https://ibb.co/4F08ybc

Any suggestions? I've tried to do a "reset" of the settings but that doesn't seem to help :/

UPDATE: I just installed 2.99.14 beta, and it showed:


Quote:gimp-user-install: migrating from C:\Users\Andy\AppData\Roaming\GIMP\2.10
Gimp-Config-Message: 15:24:31.556: Error while parsing 'C:\Users\Andy\AppData\Roaming\GIMP\2.99\gimprc' in line 14: invalid value 'convert' for token color-profile-policy
Gimp-Config-Message: 15:24:31.558: There was an error parsing your 'gimprc' file. Default values will be used. A backup of your configuration has been created at 'C:\Users\Andy\AppData\Roaming\GIMP\2.99\gimprc~'.
This is a development version of GIMP.  Debug messages may appear here.


I wonder if that was the issue? It exports fine as a JPG from the beta



TIA

Andy

RE: I've broken my exports as JPG somehow - Ofnuts - 03-18-2023

(03-18-2023, 03:11 PM)andrewnewby Wrote: I was playing around with my settings, as I always want JPG's to export at 100% quality

100% serves little purpose. Especially if in the advanced options you are not using 4:4:4 subsampling because you then have binned some of the color information.
But even with full chroma, at 100% quality some complex computations take place and produce round-off errors. Might as well save as PNG then...

(03-18-2023, 03:11 PM)andrewnewby Wrote: (it always seems to want to downgrade to 90%?).

Just click the Save defaults button at the bottom of the dialog to set your current values as the default.

(03-18-2023, 03:11 PM)andrewnewby Wrote: Anyway - now when I export an image as a .jpg I get a corrupted image. Here is my settings:

https://ibb.co/bJht60W

(sorry, I don't seem to be able to embed images via , and the upload attachment doesn't seem to work?)

Anyhow - if I look at the generated .jpg file in Notepad++, I can see it has the right start:

ÿØÿà JFIF
So far this is perfectly normal. Now, if you save the file with NP++ you'll likely break it.

The upload attachment works if your image is under 500K.

(03-18-2023, 03:11 PM)andrewnewby Wrote: So I'm unsure whats going on :/ When I try and open it in Photos I get:

https://ibb.co/4F08ybc

Any suggestions? I've tried to do a "reset" of the settings but that doesn't seem to help :/

Did you try other image viewers (like your browser)? The "progressive" setting (in the Advanced options that you didn't open) is known to break other apps (even though it is only implementing a part of the JPEG standard which is 20 years old...). Since it serves little purpose in modern days (mostly meant to have some of the image display while loading with slow internet connection) I believe it is no longer set by default in the recent versions.  

(03-18-2023, 03:11 PM)andrewnewby Wrote: UPDATE: I just installed 2.99.14 beta, and it showed:


Quote:gimp-user-install: migrating from C:\Users\Andy\AppData\Roaming\GIMP\2.10
Gimp-Config-Message: 15:24:31.556: Error while parsing 'C:\Users\Andy\AppData\Roaming\GIMP\2.99\gimprc' in line 14: invalid value 'convert' for token color-profile-policy
Gimp-Config-Message: 15:24:31.558: There was an error parsing your 'gimprc' file. Default values will be used. A backup of your configuration has been created at 'C:\Users\Andy\AppData\Roaming\GIMP\2.99\gimprc~'.
This is a development version of GIMP.  Debug messages may appear here.
I wonder if that was the issue? It exports fine as a JPG from the beta
TIA

Andy

Possibly the "Progressive" flag that was reset by your re-installation. This said 2.99 isn't recommended for everyday use, in particular it breaks many scripts and plugins. You are better off with 2.10.

RE: I've broken my exports as JPG somehow - andrewnewby - 03-18-2023

Thanks for the reply. Yes, I'm aware you can't edit images in NP++ , I just wanted to see if the first lines looked ok :Smile (I wouldn't have tried saving)

I tried the tip for the "Progressive" stuff, but still no joy. I did a 1000x1000 blank white image, and then saved it as test.jpg. It came out corrupted (won't open in anything), and 1kb in size. I then tried that same image as a .png and it works fine (but is 9kb)

Trying to open the .jpg version even in firefox, I just get:


[attachment=9547]

I'm happy to keep using 2.99 for now. Most of my work is just resizing and adding watermarks, so I don't mind if it crashes every so often :Smile quite like the new setup and layout with 2.99!

RE: I've broken my exports as JPG somehow - Ofnuts - 03-18-2023

(03-18-2023, 05:01 PM)andrewnewby Wrote: Thanks for the reply. Yes, I'm aware you can't edit images in NP++ , I just wanted to see if the first lines looked ok :Smile (I wouldn't have tried saving)

I tried the tip for the "Progressive" stuff, but still no joy. I did a 1000x1000 blank white image, and then saved it as test.jpg. It came out corrupted (won't open in anything), and 1kb in size. I then tried that same image as a .png and it works fine (but is 9kb)

Trying to open the .jpg version even in firefox, I just get:




I'm happy to keep using 2.99 for now. Most of my work is just resizing and adding watermarks, so I don't mind if it crashes every so often :Smile quite like the new setup and layout with 2.99!

Can you attach the bad JPG?

RE: I've broken my exports as JPG somehow - andrewnewby - 03-19-2023

(03-18-2023, 06:11 PM)Ofnuts Wrote:
(03-18-2023, 05:01 PM)andrewnewby Wrote: Thanks for the reply. Yes, I'm aware you can't edit images in NP++ , I just wanted to see if the first lines looked ok :Smile (I wouldn't have tried saving)

I tried the tip for the "Progressive" stuff, but still no joy. I did a 1000x1000 blank white image, and then saved it as test.jpg. It came out corrupted (won't open in anything), and 1kb in size. I then tried that same image as a .png and it works fine (but is 9kb)

Trying to open the .jpg version even in firefox, I just get:




I'm happy to keep using 2.99 for now. Most of my work is just resizing and adding watermarks, so I don't mind if it crashes every so often :Smile quite like the new setup and layout with 2.99!

Can you attach the bad JPG?

Sure - please find it attached. Interestingly, the preview works in the post - but when you click on it you get an error

RE: I've broken my exports as JPG somehow - Ofnuts - 03-19-2023

In fact you managed to create a very special JPG: since there is no green or blue component, these two colors are encoded on one bit, and this obviously surprises some image viewers (but not all). The slightest hint of another color would make is a more expected JPG. So yes, Gimp has a bug with this very specific image (which would be a lot better as PNG anyway), but as far as I can tell this is only for this image and other image would be readable everywhere.

This said, I can't recreate the problem: if I export an image filled with a pure #F0000 I do get a very small JPEG but it has a 8-bit blue channel and displays without errors in Firefox. The difference could be in the advanced options... Can you make a screenshot of the advanced options that you used?

RE: I've broken my exports as JPG somehow - andrewnewby - 03-19-2023

haha. That was just a basic image with a background. Here is an actual example of what I found when I came across the issue

The attachment should be here but isn't showing.... 

[attachment=9551]

FWIW, I can see "Progressive" is ticked, and I've also tried it unticked but with the same result

[attachment=9552]

Thanks!

Andy

RE: I've broken my exports as JPG somehow - rich2005 - 03-19-2023

This is your TEST-portrait_of_a_Leonard_McCoy_in_steampunk_attire.jpg still 100 quality but with exif / thumbnail / colour profile unticked in the  export dialog.

[attachment=9553]

hmm..about 6 KB larger file size than original.

Edit: This error opening the original in my linux viewer

[attachment=9554]

...never seen that one before...

RE: I've broken my exports as JPG somehow - PixLab - 03-20-2023

(03-19-2023, 05:24 PM)andrewnewby Wrote: FWIW, I can see "Progressive" is ticked, and I've also tried it unticked but with the same result

This is the culprit (I did try it few years ago and got errors with some software), you need to un-tick it (you did tick it because by default it is not ticked)
[attachment=9558]

When you hover it in GIMP for a second or two, GIMP is telling you that older software can have trouble to open image encoded with this (no only older software IMO Wink )
[attachment=9559]

RE: I've broken my exports as JPG somehow - Ofnuts - 03-21-2023

Some more info on arithmetic coding: http://www.rw-designer.com/entry/1311