P3D How to query image dimensions programmatically?

["marble" <marble@xxxxxxxxxxx>]

Hi,
    I have an html question for you, if you are interested.......

    im trying to write a vb program that acts like a browser for .jpg files.
So this program asks (open file dialog) for the 2 .jpgs, then writes out a
html file, and uses an api call to bring up the new web page.

    the reason im writing this is because i want a way to quickly bring up a
pair of images for 3d viewing.

    my problem is that these images are 1) sometimes really big, so defining
their height and width is a good idea.  2) not all the same dimensions.
roughly, some will be 35mm,  some will be square (old german Realist format)
.  and of the square ones, they're not all the same exact dimensions.

    if it were as simple as being able to write the height definition into
the html, and leaving out the width, my problems would be over.   but doing
that means the image will default to its real width, which is often way too
long for an image that's probably been reduced in height already.

    is there some way to query an image file to find out its dimensions?
if i knew its real height & width, i could get a ratio, and then derive the
new width based on my constant height.

    for an example of what im thinking of, see
http://www.halcyon.com/marble/3d/TestProg.htm  .

    any ideas?

Thanks,
Frank



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