Comments on: Fast 3D Stereo Vision http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/ computer vision, science, business, and life Wed, 21 Jul 2010 17:43:29 -0400 http://wordpress.org/?v=2.8 hourly 1 By: congkhanhtruong http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1391 congkhanhtruong Tue, 06 Jul 2010 14:51:38 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1391 Hi, thanks for your code. When I tried using the Tsukuba pictures, I get the same result as your picture. But if I use your code with my pictures, there are a few problems. Matlap give my images the Value 382x512 uint8, in Tsukuba, it is 288x284x3 uint8 That's a problem. Can you tell me how can I convert my images so that the code is running? Thanks for your help. Hi, thanks for your code.
When I tried using the Tsukuba pictures, I get the same result as your picture.
But if I use your code with my pictures, there are a few problems.
Matlap give my images the Value 382×512 uint8, in Tsukuba, it is 288×284x3 uint8
That’s a problem.
Can you tell me how can I convert my images so that the code is running?

Thanks for your help.

]]> By: rick http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1387 rick Thu, 24 Jun 2010 08:58:29 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1387 when i give this command mex modefilt2_mex.cpp this error comes up.... Warning: You are using gcc version "4.4.1". The version currently supported with MEX is "4.2.3". For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release/ pls help when i give this command

mex modefilt2_mex.cpp

this error comes up….

Warning: You are using gcc version “4.4.1″. The version
currently supported with MEX is “4.2.3″.
For a list of currently supported compilers see:
http://www.mathworks.com/support/compilers/current_release/

pls help

]]> By: Karthik http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1351 Karthik Wed, 05 May 2010 16:23:08 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1351 Dear Shawn, thank you very much for your rapid response. I guess, this accuracy is enough for my work. However, now that I have the disparity map, I want to calculate the depth map from it. I have all the camera parameters. So how do I calculate the depth maps? I know some formulas that use the disparity value to calculate the depth map,but is there a place where I can find the code to do the same? Or if it is easy to code, can I do it myself? Please advise me. Here are the camera parameters I have: f = 24,287 mm (focal length) Znear = 0 m Zfar = 30m Distance between left and right camera: 68mm Dear Shawn, thank you very much for your rapid response. I guess, this accuracy is enough for my work. However, now that I have the disparity map, I want to calculate the depth map from it. I have all the camera parameters. So how do I calculate the depth maps? I know some formulas that use the disparity value to calculate the depth map,but is there a place where I can find the code to do the same? Or if it is easy to code, can I do it myself? Please advise me. Here are the camera parameters I have:

f = 24,287 mm (focal length)
Znear = 0 m
Zfar = 30m
Distance between left and right camera: 68mm

]]> By: Shawn Lankton http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1349 Shawn Lankton Tue, 04 May 2010 12:48:57 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1349 <a href="#comment-1348" rel="nofollow">@Karthik </a> Great comments, and thanks for the links to your own examples. You may be right that the 'left' and 'right' inputs are flipped, but it looks like you figured that out! As for improved detail and good performance despite a lack of texture... This simple stereo vision algorithm has it's limitations! You can refer to the literature (publications like CVPR, PAMI, TIP) to find much more sophisticated algorithms that may help address the problems you mentioned. @Karthik
Great comments, and thanks for the links to your own examples. You may be right that the ‘left’ and ‘right’ inputs are flipped, but it looks like you figured that out!

As for improved detail and good performance despite a lack of texture… This simple stereo vision algorithm has it’s limitations! You can refer to the literature (publications like CVPR, PAMI, TIP) to find much more sophisticated algorithms that may help address the problems you mentioned.

]]> By: Karthik http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1348 Karthik Mon, 03 May 2010 17:38:39 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1348 I compared the images that you used with my test sequences and I noticed that I need to give the inputs as i did in the image of the second link above. However, the output lacks detail and if I decrease the window size, it does not improve. Also, if you notice the roof of the room in the image(second link), it has blue stripes that follow the texture in the original image. Any ideas how to avoid this? Thanks a lot. -Karthik. I compared the images that you used with my test sequences and I noticed that I need to give the inputs as i did in the image of the second link above. However, the output lacks detail and if I decrease the window size, it does not improve. Also, if you notice the roof of the room in the image(second link), it has blue stripes that follow the texture in the original image. Any ideas how to avoid this?
Thanks a lot.
-Karthik.

]]> By: Karthik http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1346 Karthik Mon, 03 May 2010 13:01:14 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1346 Here is the result with the correct inputs - http://picasaweb.google.com/karthik.divakaruni/DisparityMapRoom3D#5467026926067829202 Here is the result with right and left interchanged - http://picasaweb.google.com/karthik.divakaruni/DisparityMapRoom3D#5467027926374654338 Here is the result with the correct inputs – http://picasaweb.google.com/karthik.divakaruni/DisparityMapRoom3D#5467026926067829202

Here is the result with right and left interchanged –
http://picasaweb.google.com/karthik.divakaruni/DisparityMapRoom3D#5467027926374654338

]]> By: Karthik http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1345 Karthik Mon, 03 May 2010 12:47:26 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1345 Hello Shawn, I am a student working on 3D video coding project. Initially I have to get some depth maps. I am using your code to calculate the disparity maps of stereo pairs. I am using the test sequences from http://www.3dtv-research.org/publicSwLibrary.php website. I am not getting good results but I noticed a very strange thing that my results are better when i interchange the input images - Right and left. I guess it has something to do with trying out different value for MAXS - I did, but it is not working. Can you advise me on this please? Thank you so much. Hello Shawn,
I am a student working on 3D video coding project. Initially I have to get some depth maps. I am using your code to calculate the disparity maps of stereo pairs. I am using the test sequences from http://www.3dtv-research.org/publicSwLibrary.php website. I am not getting good results but I noticed a very strange thing that my results are better when i interchange the input images – Right and left.
I guess it has something to do with trying out different value for MAXS – I did, but it is not working. Can you advise me on this please? Thank you so much.

]]> By: Waqas http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1299 Waqas Thu, 25 Mar 2010 20:02:26 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1299 Hellow Yawn, I have not found the matrix.h, mex.h and except.h files. Please help me where I can find these files to run the programm. I have search these files on google and download, but when I run the programm it gives errors. Hellow Yawn,
I have not found the matrix.h, mex.h and except.h files. Please help me where I can find these files to run the programm. I have search these files on google and download, but when I run the programm it gives errors.

]]> By: emy http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1266 emy Sat, 30 Jan 2010 12:06:17 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1266 @ Ray thank you so much about your answer, i setup mex and when i write this line mex f:\modefilt2_mex.cpp the resulte is Error F:\modefilt2_mex.cpp: 82 illegal expression Error F:\modefilt2_mex.cpp: 82 found `int' expected a function Error F:\modefilt2_mex.cpp: 82 operands of = have illegal types `int' and `void' Error F:\modefilt2_mex.cpp: 100 illegal expression Error F:\modefilt2_mex.cpp: 100 found `int' expected a function Error F:\modefilt2_mex.cpp: 100 operands of = have illegal types `int' and `void' 6 errors, 0 warnings C:\MATLAB7\BIN\WIN32\MEX.PL: Error: Compile of 'F:\modefilt2_mex.cpp' failed. ??? Error using ==> mex Unable to complete successfully so what can i do??!! , i can't deal with c. regards emy @ Ray
thank you so much about your answer, i setup mex and when i write this line
mex f:\modefilt2_mex.cpp the resulte is
Error F:\modefilt2_mex.cpp: 82 illegal expression
Error F:\modefilt2_mex.cpp: 82 found `int’ expected a function
Error F:\modefilt2_mex.cpp: 82 operands of = have illegal types `int’ and `void’
Error F:\modefilt2_mex.cpp: 100 illegal expression
Error F:\modefilt2_mex.cpp: 100 found `int’ expected a function
Error F:\modefilt2_mex.cpp: 100 operands of = have illegal types `int’ and `void’
6 errors, 0 warnings

C:\MATLAB7\BIN\WIN32\MEX.PL: Error: Compile of ‘F:\modefilt2_mex.cpp’ failed.

??? Error using ==> mex
Unable to complete successfully

so what can i do??!! , i can’t deal with c.
regards
emy

]]> By: Ray Phan http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/comment-page-1/#comment-1262 Ray Phan Fri, 29 Jan 2010 01:12:20 +0000 http://www.shawnlankton.com/2008/04/stereo-vision-update-with-new-code/#comment-1262 <a href="#comment-1258" rel="nofollow">@emy </a> You have to set up MEX so that it knows what compiler to use to compile the code. Type in mex -setup in MATLAB to set that up. Hope this helps, - Ray. @emy

You have to set up MEX so that it knows what compiler to use to compile the code. Type in mex -setup in MATLAB to set that up.

Hope this helps,
- Ray.

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