JPEG 12 bits lossy

[gangli59]

Does IPP JPEG support 12bits(16bits) lossy compression?
I saw in sample JPGView, the 16 bits gray scal image JPEG lossy compression is disabled.

[Thomas_Jensen1]

Quoting - gangli59

Does IPP JPEG support 12bits(16bits) lossy compression?
I saw in sample JPGView, the 16 bits gray scal image JPEG lossy compression is disabled.

It does.
When the loaded image has Precision = 12 bit, you can save as 12 bit lossy (Jpeg mode = Extended).

[gangli59]

Quoting - Thomas Jensen

It does.
When the loaded image has Precision = 12 bit, you can save as 12 bit lossy (Jpeg mode = Extended).

In JPGView, I can load both 16 bit's pgm and 16 bits jpeg lossless files, but can not save as lossy format. The save as dialog box only allows me to select lossless format.

[Vladimir_Dudnik]

And the reason is that according JPEG standard you can only store 12-bit images in JPEG Extended Baseline 12-bit Lossy mode.

We do not truncate image data in UIC demo applications andtake more straightforward approach instead. The application logic only allow you to store image in format which will not cause bits truncation. For 16-bit images it is PNM, JPEG lossless or JPEG2000 formats. For 12-bit images it is PNM, JPEG Extended Baseline 12-bit Lossy, JPEG lossless and JPEG2000 formats. And for 8-bit images you additionally can store images in BMP and DDS formats.

Regards,
Vladimir