A
Andreas Viklund via DotNetMonster.com
Hi!
I am developing an application in ASP.NET that takes an image, that have
been created with a digital camera or camera phone, and processes it, to
get data from it. The image taken by the user will be of a square in some
kind of magazine or newpaper, with a white background and the border of the
square should be black.
What I am trying to do is to find the square, or the corners of the square,
in the image, using ASP.NET code. If the user always took the picture
directly above the square without any rotation and blur this would not be a
big problem. But that is hardly not the case most of the times.
What I have managed to do so far is to convert the image to gray scale and
then made some kind of thresholding so I will end up with just white and
black pixels. This will make the square very visible in the image, but so
will other dark object, even if alot is taken out in the tresholding.
Finding one of the corners in the square, and always be positively sure
that you have found it, would solve alot. Then I think I can manage to do
the rest. In my solution now, I will sometimes find a corner, but it does
not work for many images.
Does some one have an idea of how to solve this problem? I have tried
different ways of search for objects in the image by looking at all pixels,
but I really dont know how to see the difference between the corner of the
square and an object.
Is it possible to search for patterns in the image? like if I search the
image after objects that are similar to a corner of a square.
I would really like some help with this problem. All kinds of ideas are
welcomed!
Best Regards
Andreas Viklund
UMEA, Sweden
I am developing an application in ASP.NET that takes an image, that have
been created with a digital camera or camera phone, and processes it, to
get data from it. The image taken by the user will be of a square in some
kind of magazine or newpaper, with a white background and the border of the
square should be black.
What I am trying to do is to find the square, or the corners of the square,
in the image, using ASP.NET code. If the user always took the picture
directly above the square without any rotation and blur this would not be a
big problem. But that is hardly not the case most of the times.
What I have managed to do so far is to convert the image to gray scale and
then made some kind of thresholding so I will end up with just white and
black pixels. This will make the square very visible in the image, but so
will other dark object, even if alot is taken out in the tresholding.
Finding one of the corners in the square, and always be positively sure
that you have found it, would solve alot. Then I think I can manage to do
the rest. In my solution now, I will sometimes find a corner, but it does
not work for many images.
Does some one have an idea of how to solve this problem? I have tried
different ways of search for objects in the image by looking at all pixels,
but I really dont know how to see the difference between the corner of the
square and an object.
Is it possible to search for patterns in the image? like if I search the
image after objects that are similar to a corner of a square.
I would really like some help with this problem. All kinds of ideas are
welcomed!
Best Regards
Andreas Viklund
UMEA, Sweden