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Science Forum Index » Image Processing Forum » How to cut rectangle object from the image
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| Chandresh |
 Posted: Sun Jan 07, 2007 8:06 pm |
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Guest
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Hi all,
I have a video data stream recorded by a camera mounted on a robot in
indoor environment. I have created an object in Matlab that acquires
the video data and using matlab function I am able to get the image
frames from the data so now I have an image that contains rectangle (or
square) number plate. I want to cut this rectangle number plate area
from the image to do further analysis. How can I do it in Matlab? Your
help is greatly appreciated as my work is more related to path
planning. Any kind of help that makes my work more specific is welcome.
Thanks & regards,
Chandresh |
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| RoboRealm |
| Posted: Sun Jan 07, 2007 11:55 pm |
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Guest
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Hi,
Its a little hard to tell you an easy way to do that without seeing an
image. For example, if you are working on a European license plate then
detecting yellow squares would be you best bet ... some even have
reflective coatings that shine in IR lighting that makes things easier
to detect.
Perhaps you can post a couple images (you're welcome to post in
http://www.roborealm.com/forum.php and include images) so that we can
better understand what you are working on.
STeven.
www.roborealm.com
Chandresh wrote:
Quote: Hi all,
I have a video data stream recorded by a camera mounted on a robot in
indoor environment. I have created an object in Matlab that acquires
the video data and using matlab function I am able to get the image
frames from the data so now I have an image that contains rectangle (or
square) number plate. I want to cut this rectangle number plate area
from the image to do further analysis. How can I do it in Matlab? Your
help is greatly appreciated as my work is more related to path
planning. Any kind of help that makes my work more specific is welcome.
Thanks & regards,
Chandresh |
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| Back to top |
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| python |
| Posted: Mon Jan 08, 2007 1:58 am |
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Guest
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I think "hough transform" can help you detect the rectangles number
plate , howerver, the
built-in function of hough is only available for detecting lines, so
for detecting rectangles you may google "hough rectangle".
Good lucks!
"Chandresh дµÀ£º
"
Quote: Hi all,
I have a video data stream recorded by a camera mounted on a robot in
indoor environment. I have created an object in Matlab that acquires
the video data and using matlab function I am able to get the image
frames from the data so now I have an image that contains rectangle (or
square) number plate. I want to cut this rectangle number plate area
from the image to do further analysis. How can I do it in Matlab? Your
help is greatly appreciated as my work is more related to path
planning. Any kind of help that makes my work more specific is welcome.
Thanks & regards,
Chandresh |
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| Back to top |
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| serg271 |
| Posted: Mon Jan 08, 2007 2:24 am |
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Guest
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Quote:
I have a video data stream recorded by a camera mounted on a robot in
indoor environment. I have created an object in Matlab that acquires
the video data and using matlab function I am able to get the image
frames from the data so now I have an image that contains rectangle (or
square) number plate. I want to cut this rectangle number plate area
from the image to do further analysis.
Identify all quadrilateral contours in the image (use edge detector or
image segmentation). For each quadrilateral make projective transform
to rectangle. You can get rectangle plane vector as n = (L0 X L2) X (L1
X L3), Li - line equation for side of quadrilateral (Li.x*X + Li.y*Y +
Li.z =0)
After you get plane equation project quadrilateral into that plane,
quadrilateral become rectangle or parallelepiped(in that case make
affine transform). Inside area of quadrilateral project into
undistorted image(+noise). Use any correlation function to detect
digits of the number now. |
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| Chandresh |
| Posted: Tue Jan 09, 2007 10:34 pm |
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