Comparing Images

Lets say i have 2 images, a.jpg and b.jpg
Both are actually one same picture of a bear but have different filenames.
is there anyway in .net that i can find out if the two pictures are actually
same even if the filename is different.

Re: Comparing Images

Hi Solitus,

If you are talking about byte by byte comparsion, not graphic recognition,
you could load the image into memory using Image object and compare them
byte by byte or by hash.

However this seems not related to ASP.NET? :-)

Regards,
Jack Li
MVP (ASP.NET)

"Solitus" wrote in message
news:EF760CFD-434F-4B37-82F5-335ACA4C7064@microsoft.com...
> Lets say i have 2 images, a.jpg and b.jpg
> Both are actually one same picture of a bear but have different filenames.
> is there anyway in .net that i can find out if the two pictures are
> actually
> same even if the filename is different.

Re: Comparing Images

So if i have image A showing a bear and image B showing what A shows,
comparing byte by byte or hash will verify if they are equal?

"Jack Li" wrote:

> Hi Solitus,
>
> If you are talking about byte by byte comparsion, not graphic recognition,
> you could load the image into memory using Image object and compare them
> byte by byte or by hash.
>
> However this seems not related to ASP.NET? :-)
>
> Regards,
> Jack Li
> MVP (ASP.NET)
>
> "Solitus" wrote in message
> news:EF760CFD-434F-4B37-82F5-335ACA4C7064@microsoft.com...
> > Lets say i have 2 images, a.jpg and b.jpg
> > Both are actually one same picture of a bear but have different filenames.
> > is there anyway in .net that i can find out if the two pictures are
> > actually
> > same even if the filename is different.
>
>
>

Re: Comparing Images

Hi Solitus,

For byte by byte compare, two image must be EXACTLY the same, even if they
are different by one pixel only, they are different. However, to human eye,
if two image are differ only by a very little amount, we may consider they
are the same, those differents may be caused by file compression too.

Regards,
Jack Li
MVP (ASP.NET)

"Solitus" wrote in message
news:F1A93091-CCB2-4CA7-B38B-99B3BCD26CAD@microsoft.com...
> So if i have image A showing a bear and image B showing what A shows,
> comparing byte by byte or hash will verify if they are equal?
>
> "Jack Li" wrote:
>
>> Hi Solitus,
>>
>> If you are talking about byte by byte comparsion, not graphic
>> recognition,
>> you could load the image into memory using Image object and compare them
>> byte by byte or by hash.
>>
>> However this seems not related to ASP.NET? :-)
>>
>> Regards,
>> Jack Li
>> MVP (ASP.NET)
>>
>> "Solitus" wrote in message
>> news:EF760CFD-434F-4B37-82F5-335ACA4C7064@microsoft.com...
>> > Lets say i have 2 images, a.jpg and b.jpg
>> > Both are actually one same picture of a bear but have different
>> > filenames.
>> > is there anyway in .net that i can find out if the two pictures are
>> > actually
>> > same even if the filename is different.
>>
>>
>>

Re: Comparing Images

On Mar 29, 1:35 am, Peter Bromberg [C# MVP]
wrote:
> I think you want to look for something closer to face recognition or motion
> detection algorithms, or a classifier type of neural net.
> -- Peter
> Site:http://www.eggheadcafe.com
> UnBlog:http://petesbloggerama.blogspot.com
> Short Urls & more:http://ittyurl.net
>
>
>
> "Maxus" wrote:
> > Hi Everyone,
>
> > Just wondering if anyone knew of a way to compare images and getting a
> > nearest matching image out of a collection of images of diffrent
> > sizes, colors, etc. Ideally want to compare the general shape of the
> > main features in the image, would be nice if it also compared the
> > average color value. I've done a bit of hunting on google and only
> > really come up with solutions that match pictures based on their file
> > hash value or solutions that are pure math without some general guides
> > on implementation in C#.
>
> > Thanks in advance,
> > Max- Hide quoted text -
>
> - Show quoted text -

Hi Peter,

Thanks for your feedback; to be honest it's to make a simple piece of
software that generates those mosaic pictures, just a simple personal
project. Can you provide some reference material explaining some of
the mentioned suggestions? I have looked over those topics previously,
but had difficulty finding a way to use them.

Thanks,
Max

Re: Comparing Images

On Mar 28, 6:08=A0am, Maxus wrote:
> I've done a bit of hunting on google and only
> really come up with solutions that match pictures based on their file
> hash value or solutions that are pure math without some general guides
> on implementation in C#.

C# implementation
http://www.codeproject.com/KB/GDI-plus/comparingimages.aspx
http://www.google.com/search?hl=3Den&q=3Dcompare+images+hash +.net

Hope this helps