Arithmetic decoding disabled in libjpeg-turbo

[jgutierrez]

It seems that XnViewMP is not able to decoded JPEG files that use arithmetic encoding as opposite of Huffman. Since it is using libjpeg-turbo, it should be as easy as compiling with the define D_ARITH_CODING_SUPPORTED.

Is there any chance it would be added in future builds?

Thanks.

[xnview]

ok, do you have such jpeg?

[jgutierrez]

Sure!

Find attached some requested samples, nevertheless, you can always use jpegtran -aritmetic in order to convert a regular Huffman JPEG to Aritmetic, or jpegtran -optimize to do the oposite.

For your information, GIMP is able to view and edit arithmetic JPEG images with no problems too.

arithmetic_jpeg.zip

[jgutierrez]

Hello Pierre,

Were the samples I provided enought for you?
Do you want some more?

Thanks.

[xnview]

thanks, i'll check

[XnTriq]

* JPEG arithmetic decoding support - http://newsgroup.xnview.com/viewtopic.p ... 7&p=105449

Tested successfully with the samples provided by jgutierrez

• JPEG Arithmetic
• New, enhanced JPEG format

[dma_k]

I've just read two other related topics (Cant view lossless jpg and JPEG v9.1 now supports 12-bit color and lossless compression) and I wonder if JPEG arithmetic decoding is implemented in XnView Classic? As for XnView 2.35, it seems not to support arithmetic-encoded images.

[XnTriq]

[…] and I wonder if JPEG arithmetic decoding is implemented in XnView Classic? As for XnView 2.35, it seems not to support arithmetic-encoded images.

I just did a quick test with an arithmetic coded JPEG saved by Jpegcrop (2015.12 / IJG JPEG 9b). XnView MP v0.83 is able to open the file, but Classic v2.39 can't.