Re: Forms 4.5 Loading images problem

Suzanne Edgecombe wrote:

>
>
> I have created several Forms with Image objects to allow our
> scientists to load images of their rock samples. We decided to limit
> the image file type to jpgs (JFIF) for space conservation.
>
> The user is able to type in a path name and a trigger on a button
> which reads:
>
> read_image_file (:blockname.path, 'JFIF', 'sketch');
>
> activates.
>
> I have discovered that my forms are rather selective about the jpg
> images that they will accept - the following scenarios have occurred
> (all files transferred to UNIX environemnt using RapidFiler):
>
> File 1. Downloaded BMP file from internet, opened in Paintshop Pro
> and saved as .JPG. Transferred to Unix environment, I type in the file
> path and it loads.
>
> File 2. Scan in image and save as JPG.Transferred to Unix, I type in
> the file name and the "working" message VERY briefly appears at the
> base of the form and then nothing - the file does not load, but no
> error occurs. I then went back to the Windows environment, resaved
> the file using PSP as a JIF file, and found that this loads perfectly.
>
> File 3. Digitally captured image from a microscope saved as JPG does
> not load, this is then saved as a BMP, change the file type accepted
> in the trigger and this loads. Resave this image as a JPG file and
> try loading again (changing the accepted file type back to JFIF in the
> trigger), and it loads perfectly.
>
> Does anyone understand what is happening and how to get around this
> problem in such a way that my users (some of whom are not particularly
> comfortable with databases) can cope with this issue?
>
> Many thanks
>
> Suzanne Edgecombe
> "The number of the beast - vi vi vi"

  Since I sent this yesterday, I have managed to discover a solution to the problem. I thought that I would post it, since I figured if I have this problem then so will others. So here tis.....

It seems that some software (eg some software that comes with some scanners and digital cameras) when told to save an image as a JPG writes a file header that is non JFIF compliant. It looks and smells like a JPG, but is not JFIF compliant.

The only way to change this header is to overwrite it by saving as another format (eg: BMP). You can then resave as a JPG and this file header is rewritten back to JPG format, a compliant version, which will then load no problemo!!!

Hope this is of use......

Cheers, Sue E Received on Tue Aug 18 1998 - 18:31:25 CDT