Re: Image file name extension not recognized

[Vinicius Jose Latorre <viniciusjl@ig.com.br>]

Chong Yidong wrote:
> Vinicius Jose Latorre <viniciusjl@ig.com.br> writes:
>
>   
>> I have some image files with names like:
>>
>>    IMG_0366.JPG
>>
>> When I try to open it, Emacs does not recognize it as an image file.
>>
>> But if I rename the file to:
>>
>>    IMG_0366.jpg
>>
>> Then Emacs recognizes the file as an image file.
>>
>> Shouldn't Emacs recognize files with .JPG extension as an image file?
>>     
>
> Jpeg images are supposed to be autodetected using their contents, even
> if the file extension is JPG (see image-type-header-regexps).
> Apparently, that autodetection is failing in this case.  Could you try
> to find out why?

The image-type-header-regexps variable has the value:

  '(("\\`/[\t\n\r ]*\\*.*XPM.\\*/" . xpm)
    ("\\`P[1-6]" . pbm)
    ("\\`GIF8" . gif)
    ("\\`\211PNG\r\n" . png)
    ("\\`[\t\n\r ]*#define" . xbm)
    ("\\`\\(MM\0\\*\\|II\\*\0\\)" . tiff)
    ("\\`[\t\n\r ]*%!PS" . postscript)
    ("\\`\xff\xd8" . (image-jpeg-p . jpeg)))

Where image-jpeg-p is a function.

I just type  M-x debug-on-entry RET image-jpeg-p RET

Then tried to open the file again and image-jpeg-p is not called.