Add support for new version of libpng

Hello everybody.
I would like the gimp developers to update the file libraries of image formats such as libpng which was released 3 days ago libpng in version 1.6.40 and other image formats which have not been updated yet.
Thanks in advance.
If I’m in the wrong forum asking or requesting a feature in this forum that might be different, please correct me and I apologize to everyone.
Thanks in advance.

You should be a bit more specific about what you want to be updated, and for what reasons.

It’s basically like this… let’s say that a long time ago, when the first version of png or jpg was released, I couldn’t make many color changes to the image or add a color to that photo that has that format, whether it’s png or jpg.
I’m wrong, but when I used Photoshop, I noticed that a screen quality print file on my notebook at 1366x768 resolution was around a very few kb in file size, although I don’t know if Gimp or Photoshop keeps the DLL’s of updated image formats, it is always important, as a print screen image without any modifications in Photoshop or gimp, I noticed that in Photoshop the image size in MB or KB is smaller than in gimp, and the print image is saved as png standard image, transition and quality without any cropping or modification, the quality and size of the image is inferior.
If the developers update with each new version (not beta version, just the final version of each dll or library) of image format libraries and dlls, such as png, gif, jpeg, jpg, tiff, svg and other various formats that fortunately gimp supports.
It will be a great and splendid thing, something that Photoshop cannot do, keeping the image formats in dll or updated libs library, it is easily possible to have more possibilities to generate images and transitions easily without spending a lot of ram or cpu depending on the resolution or image bit rate, and thus having a better quality.
It’s the same thing between c language and python, python is one of the most advanced nowadays.
Definitely keeping these dll formats and libraries up to date, we can have more image quality and less size in MB or kb in our images.
That’s it anyway. Thanks in advance.

… to be honest, I expected something like “older libpng versions have the following serious bug, which is fixed in 1.6.40” or “libpng 1.6.40 adds support for …”

The png format itself has not changed in 20 years. You can read it here:

GIMP generally uses the latest version of libpng on Linux and Mac systems; on Windows, the latest version is normally used whenever a new version of GIMP is released. However, updates to libpng do NOT affect any of the issues you mention.

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I understand, I believe that little information is added over the years in the quality of the png format, when updating the termux files on my smartphone, I noticed that the libpng version was updated recently, with the command I used: pkg upgrade and pkg update

I believe these sources are reliable: LIBPNG: PNG reference library download |

Keeping there, their updated repositories and official developers websites, here is obviously the official website:

Although I noticed a difference in color quality and less kb in png image size between Photoshop and gimp, I could see that Photoshop gained a little more advantage when using png as a print screen than png from gimp.
It probably has to be an additional dll or a more advanced API than gimp, but before that there’s not much I can say, gimp is a great tool and I’m happy to use it to save prints or edit a simple photo in the software.

It is very important that the gimp can have dlls and libraries updated in final versions or in final beta, so that we have improved quality with each edition or in each version that the software is released, thus being stronger, more robust, powerful and fluid .
Thank you for clearing my doubts. It’s great to know that gimp’s abdation is always very committed to updating the dlls and libraries and adding new tools and filters to our editions.
Thank you, and we hope that in 2023 the great and expected version 3.0 will be able to come out with pleasure.

Thanks a lot team!

What i linked to was the specification for the PNG format; libpng is one implementation of that specificaiton. So, libpng can’t add features not in the specification.

The size difference you see is most likely from different compression choices - when you export png from GIMP you can chose compression level, and higher levels will take longer but make smaller files.

PNG compression is lossless: it does not damage the image. This is different from JPEG, where compression is generally lossy, and introduces “artifacts” that damage the image. This allows JPEG images to be smaller files, because they are not as precise.

If you are seeing a quality difference, either one is using JPEG (lower quality than PNG), or it might be that you have a different colour profile set in GIMP’s or Photoshop’s preferences perhaps. It is not likely to be from a difference in libpng.


libpng is an extremely stable library. It is not one where each release brings shiny new hotness. Just look at Commits · glennrp/libpng · GitHub to convince yourself. There are mostly code cleanups and a few bug fixes.

The libpng version is not where you should look for solving your image size problems.

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It is very important that the gimp can have dlls and libraries updated in final versions or in final beta,

Beta, certainly not. Beta is by definition not stable.

Also, Gimp is used by Linux people, and on Linux, Gimp uses the libpng library which is installed/maintained by the system. Depending on the distribution used the version of this library can be anywhere between 3 months and 5 years old(*). If Gimp insists on using the latest and greatest, it becomes unable to run on a large share of existing Linux workstations.

(*) possibly even older, on RHEL systems, but these are rarely used as workstations.

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