Lemke Software GmbH Forum

Hello,
I did some exploration of the jpegtran command line tool.
I found, that the -arithmetic option achieved the smallest file size (without further loss of quality), even smaller than ImageOptim can produce.
Unfortunately GraphicConverter can't open those JPEGs while every other image processing application on my Mac* has no problem loading them. Even Preview and QuickView work.
It would be great if I could archive my JPEGs, of which I have no lossless copy, with GraphicConverter using that uncommon but very efficient format and not have to use jpegtran in the terminal for every file.
Regards
Markus

*Intel Core i7 iMac, MacOS 13.4.1
Programs tested: Preview 11.0, Safari 16.5.2, Mail 16.0, Photos 8.0, Pages 13.1, Affinity Photo 2.1.1, PhotoZoom Pro 5.1.2, Topaz Photo AI 1.5.0, PDFpenPro 13.1, GoodNotes 5.9.127, LibreOffice 7.5.4.2, Pixen 5.0.2, PikoPixel, VLC 3.0.18,
Not working: GraphicConverter 12.0.4 (6201) Beta (with both TurboJPEG and JPEG 6c) and Google Chrome 115.0.5790.170
Sample image: 9145Byte, ImageOptim: 9516Byte, that's 4.06% bigger (with larger images I got ~6% difference)

Please download BETA build 6202. That fixes the issue with this unusual codec.

http://www.lemkesoft.org/beta.html

Many thanks for providing the sample.

Thorsten

GC now opens a window with the correct dimensions, but the picture is completely white.

Ah, you have to set TurboJPEG instead of JPEG 6c in the JPEG preferences.
Thank you for implementing that.