Compare Image Objects in PDF Files Programmatically

[Fir5tSight]

Hi,

I'm sorry this may not be the right place for this topic. However, I
don't know where else I should get help. Hopefully some people here can
give me an answer on the following topic:

How to compare two images in two PDF files to see if they are
identical?

When two images are of two different sizes but if they are of the same
image, the comparison should return true because they are the same
image. It's like comparing two photos of size 4x6 and 5x7, as long as
they are the same picture, the program should tell you that they are
the same.

BTW, I use C# language, and the images are either chart or windows
metafile.

Many thanks!

-Emily

 

[Michael Nemtsev]

Hello Fir5tSight,

If you are not going to use some heuristic algorighms the best aprroach is
to extract pictures and compare them byte-to-byte

F> I'm sorry this may not be the right place for this topic. However, I
F> don't know where else I should get help. Hopefully some people here
F> can give me an answer on the following topic:
F>
F> How to compare two images in two PDF files to see if they are
F> identical?
F>
F> When two images are of two different sizes but if they are of the
F> same image, the comparison should return true because they are the
F> same image. It's like comparing two photos of size 4x6 and 5x7, as
F> long as they are the same picture, the program should tell you that
F> they are the same.
F>
F> BTW, I use C# language, and the images are either chart or windows
F> metafile.
F>
F> Many thanks!
F>
F> -Emily
F>
---
WBR,
Michael Nemtsev :: blog: http://spaces.msn.com/laflour

"At times one remains faithful to a cause only because its opponents do not
cease to be insipid." (c) Friedrich Nietzsche

 

[Fir5tSight]

Hi Michael,

If two images are identical but of different sizes, will the
byte-by-byte comparison fail?

Thanks,

-Emily