iminfoBuglet

Psychtoolbox › PsychMatlabTests

Mathworks Case ID 187040, reported 2/99

IMINFO gives misleading error message.

>There's a minor bug in the error reporting in imjpginfo.m, which is called by
>IMFINFO
>
>'bill.jpeg' is a CMYK color jpeg file that i created in photoshop. Matlab
>doesn't know how to read that, which is ok. Your imjpg.mex file does the
>right thing, returning an empty 'info', and a 'msg' of 'Jpeg image is
>neither grayscale or RGB.'
>
>However, your imjpginfo.m then fails, with the misleading error message:
>
>+imfinfo('bill.jpg','jpg')
>??? Reference to non-existent field 'BitDepth'.
>
>Error in ==> Savoca:Applications:Matlab
>5.2:Toolbox:matlab:iofun:private:imjpginfo.m
>On line 50 ==> if (info.BitDepth == 8)
>
>The cleanest fix for this buglet would be to check that 'msg' is empty
>before accessing any fields of 'info'.


Denis,

Thanks for your report and detailed diagnosis of the JPEG imfinfo problem.
I'll fix it soon. The fix won't make it into the next release, however,
because development has been completed on it.

Thanks again,

Steve

--
Steve Eddins, image processing specialist eddins@mathworks.com
The MathWorks, Inc. http://www.mathworks.com