JPEG Translator v1.1.1
©2002-2003 by Marcin 'Shard' Konicki
shard@beosjournal.org
http://shard.beosjournal.org

TranslationKit add-on for JPEG files. Has more options and can write jpg files with far much better quality than default one in BeOS r5.

It's based on libjpeg by IJG (http://www.ijg.org/files/), with patch to support "lossless" (really bad and misinformative name) encoded images by Ken Murchison (http://www.oceana.com/ftp/ljpeg/). I also used some color space conversion routines by Magnus Hellman found in TestBMPTranslator (http://www.bebits.com/app/802).


A little explanation ("what is what"):

To install translator drag & drop "JPEGTranslator" file onto "Drag JPEGTranslator here" folder.

When You run DataTranslations application and go to JPEG Translator settings, You'll see 3 tabs:
- Write
- Read
- About

Write tab shows settings used for writing jpeg files:

Output quality let's You chose how much output image will be similar to original image. Less quality means worse output image. There is a scale from 0% to 100% but in reality 95% is maximum quality, more percent only will make output file bigger without any noticable image quality changes.

Output smoothing strength let's You chose how much blurred output image will be. It sometimes helps to make it 3-5% smoothed when You use smaller quality. Depends on what that image will be used for of course.

Use progressive compression will make output file to be loaded progressively on webpage, ie: first client will see very big pixels, than after each "rescan" of image it will get better and better up to full image. This option usually makes output file smaller.

Prevent colors 'washing out' makes output file bigger but with full colors from original file. If You made some jpg files on BeOS before, You've probably noticed colors were "washed out". This option prevents that :)

Make file smaller (slightly worse quality) is available only with previous option set on. It will make outout file smaller but with a little worse quality (from what i've seen it's like difference between quality of 95% and 93% - but it's highly subjective opinion. Some people who have seen images generated with this option said they're the same as 95%, others said they're mych worse :)

Write Black&White images as RGB24 tells translator to write B_GRAY1 images as rgb jpeg. If it's turned off, translator will write them as greyscale.


Read tab shows settings used for reading jpeg files:

Read Greyscale images as RGB32 makes translator to read greyscale images as they have been color. Most applications on BeOS can't "understand" greyscale images from translation properly (i've tried ShowImage, ViewImage, Gobe Productive 2, NetPositive, and ArtPaint - only NetPositive can understand them).

Use CMYK code with 0 for 100% ink coverage is to let You read properly CMYK color space jpeg images generated by Photoshop.

Note: CMYK support is only basic - just to give You idea how image can look. Exact translation will be available someday in the future maybe.

Show warning messages lets You turn off read warnings. There are damaged/wrongly written jpg files which can be rendered ok, or almost ok. With this option checked You'll not be bugged about missing few bytes in some image anymore ;]


About tab shows info about this translator.


Shard