XnView Software

I used the batch mode to convert my picture files with the jpeg guetzli encoder.
The settings button is disabled. Please enable it to get to the normal jpeg encoder settings,
because the guetzli encoder use them. - Thank you!

Confirmed

Hello forum!
I enjoy Xnview for many years now and i once recommended to license original Xnview for a medium big company here in germany.

Now i tested MP for the first time and like the idea it integrates the google Guetzli encoder.
I think the internal workflow is a bit strange. When i encode a png with original Guetzli the files always end bigger but with better quality.
When i open this very same png with MP it seems you encode it with the internal jpg setting first and pass this resulting jpg data to the Guetzli encoder.
The artifacts of these 2 coversions sum up in this case.
I think since the Guetzli encoder accepts png and jpg it would be better to pass uncompressed png to it.
I may totaly misunderstand how it really works but the files pretty much fit in quality and size when i reproduce it.
Guetzli may soon have OpenCL support and may deserve an own settings page. https://github.com/google/guetzli/pull/227
Also Guetzli seems to delete the dpi value. Some way to call exiftool to re-enter a dpi value like "exiftool -Xresolution=xxx -Yresolution=xxx" would be great.

It is very interesting to see a guetzli encoder project with OpenCL and CUDA support. I hope the performance increase and the required time sink to half or a quarter of the time for encoding. I tried your link, but there only are information about the project with cuda/opencl support. Is the optimized program (*.exe) for windows available?

I do not understand, why you encode PNG-Files to jpeg with guetzli encoder?
If you have PNG-files with 1-256 different colours it will be very difficult to reduce the filesize with gutzli encoder.
PNG will be better in compression, if the picture has big areas of a single file (e.g. a white background with a small logo in the middle).
I think you have a 8 bit png than png should be the best format to get smaller files.
You can optimize your png file with pnggauntlet to save a few kb in filesize.

If you have a truecolor picture guetzli and all other jpeg encoder will produce smaller filesizes.
Please check your png file!

Guetzli is meant to produce HQ jpg from png so i don't know why to argue. I need jpg in the end result.
No compiled exe of the OpenCL version around so far i guess. The chinese coders may have a .cn page i don't know about
You may misunderstand the problem. When i want to shrink existing pngs MP does create a jpg first and passes that to the Guetzli encoder.
It does not üse the existing png to Guetzli directly but encodes it with the internal routine first and then encodes again.
This could make sense when Guetzli was a repacker but it is an encoder that adds artifacts.
Try a file with Guetzli exe and MP, compare it.
Imagine another scenario like batch sizing files.
MP takes the existing jpg file, sizes it and makes it jpg before passing it to Guetzli. Again it ends in 2x reencoding.
When this is what i think it does i'd prefer Guetzli does the encode from an uncompressed png source after sizing.
I suggest handling Guetzli with an own settings page like jpeg-2000.
Atm it will only have a quality slider between 84 and 100 but i guess we will see some more functions like OpenCL or Cuda soon.

No, I understand what you mean.

I did not analyse, how XnView MP converts different files to guetzli jpg.
It is not a good idea to convert a file to normal jpeg (e.g. 100% quality) and then to guetzli jpeg.
Maybe the programmer want to prevent problems with different exotic input files,
which are not compatible with guetzli encoder! Then a loseless png input file should be better.

A seperate menue for guetzli file format settings would be great!

In the beginning I used a cmd batch file for the guetzli encoder with my favorit settings to drag & drop my picture files on it for conversion.

But a good solution for XnView MP would be great, too! We will see.

I used some cmd also. Lately a simple frontend popped up here http://www.multipetros.gr/public-projec ... /guietzli/
Having it working correctly in the MP batch conversion like your thread here asks for will be much better!

Here is another Frontend for guetzli with multi core support:

https://www.guetzliconverter.net/

To my suggestion above i saw guetzli itself will add an "--preserve-exif" option. https://github.com/google/guetzli/pull/175