Hi! All Exports,

I get some jpeg images from a film scanner. I tried to open the images with
quite a few freeware image viewers: Irfanview, xnview, imagej, IJG jpeg-6b.
All those software failed to open the images and gave error massage
"Unsupported JPEG data precision 12". What is going on? What software can I
use to convert those 12-bit (I guess) jpeg images to "Normal" jpeg?

Thanks,

Haifang Li

"Haifang Li" <haifang.li@stonybrook.edu> wrote in
news:42e1445e$1_2@marge.ic.sunysb.edu: 

> Hi! All Exports,
> 
> I get some jpeg images from a film scanner. I tried to open the images
> with quite a few freeware image viewers: Irfanview, xnview, imagej,
> IJG jpeg-6b. All those software failed to open the images and gave
> error massage "Unsupported JPEG data precision 12". What is going on?
> What software can I use to convert those 12-bit (I guess) jpeg images
> to "Normal" jpeg? 

JPEG supports either 8-bits-per-component or 12-bits. Most the world uses 8 
bits. Some medical applications use 12-bit grayscale.

Apparently you can compile the IJG software to do 12 bits if you set the 
DEFINEs correctly. I have never seen it done. It would be very difficult to 
code such than an application could support 12 and 8 bits at the same time.

Flavius Vespasianus wrote:
> "Haifang Li" <haifang.li@stonybrook.edu> wrote in
> news:42e1445e$1_2@marge.ic.sunysb.edu: 
> 
> 
>>Hi! All Exports,
>>
>>I get some jpeg images from a film scanner. I tried to open the images
>>with quite a few freeware image viewers: Irfanview, xnview, imagej,
>>IJG jpeg-6b. All those software failed to open the images and gave
>>error massage "Unsupported JPEG data precision 12". What is going on?
>>What software can I use to convert those 12-bit (I guess) jpeg images
>>to "Normal" jpeg? 
> 
> 
> JPEG supports either 8-bits-per-component or 12-bits. Most the world uses 8 
> bits. Some medical applications use 12-bit grayscale.
> 
> Apparently you can compile the IJG software to do 12 bits if you set the 
> DEFINEs correctly. I have never seen it done. It would be very difficult to 
> code such than an application could support 12 and 8 bits at the same time.

dcmtk and gdcm does it every day :)
the ijg included in gdcm should be -relatively- easy to extract to build 
for a homegrew application.

Mathieu
http://www.creatis.insa-lyon.fr/Public/Gdcm/
http://dicom.offis.de/dcmtk.php.en

I am amazed Infranview does not support 12 bit jpegs, considering their 
otherwise extensive image type support.


>> I get some jpeg images from a film scanner. I tried to open the images
>> with quite a few freeware image viewers: Irfanview, xnview, imagej,
>> IJG jpeg-6b. All those software failed to open the images and gave
>> error massage "Unsupported JPEG data precision 12". What is going on?
>> What software can I use to convert those 12-bit (I guess) jpeg images
>> to "Normal" jpeg?
>
> JPEG supports either 8-bits-per-component or 12-bits. Most the world uses 
> 8
> bits. Some medical applications use 12-bit grayscale.
>
> Apparently you can compile the IJG software to do 12 bits if you set the
> DEFINEs correctly. I have never seen it done. It would be very difficult 
> to
> code such than an application could support 12 and 8 bits at the same 
> time. 

"Max Power" <mikehack@u.washington.edu> wrote in
news:dc20cs$jkc$1@gnus01.u.washington.edu: 

> I am amazed Infranview does not support 12 bit jpegs, considering
> their otherwise extensive image type support.
>
Someone's got to do the builds in a support. AFAK, there is not accepted 
standard for 12-bpc JPEGs. So even if you compiled LIBJPEG to decode the 
data, there is no standard to tell what to do with that data.

Hi Li,

> I get some jpeg images from a film scanner. I tried to open the images 
> with
> quite a few freeware image viewers: Irfanview, xnview, imagej, IJG 
> jpeg-6b.
> All those software failed to open the images and gave error massage
> "Unsupported JPEG data precision 12". What is going on? What software can 
> I
> use to convert those 12-bit (I guess) jpeg images to "Normal" jpeg?

is it color or grayscale images?
If color - please send me one (or link to download)
I implemented support for grayscale 12-bit jpegs 
(http://reader.imagero.com), but can not find color 12-bit jpegs.

Thanks

Andrey

-- 
Andrey Kuznetsov
http://uio.imagero.com Unified I/O for Java
http://reader.imagero.com Java image reader
http://jgui.imagero.com Java GUI components and utilities

Hi!

Thank you all for replying.

After some reseach, I found that the leadtools command-line image file
converter
(http://www.leadtools.com/Utilities/Cmd-Line/File-Converter/default.htm) is
able to convert the 12-bit jpeg into bmp or other format. Also, JACS paint
shop pro v.8 is able to open those jpeg images.

Haifang Li