(OpenCV/C++) Image Rectitication/Transformation

asked 2015-02-27 15:22:48 -0500

updated 2015-02-27 19:12:13 -0500

jefferson-sep gravatar image

Hi, am new to computer vision, began Monday, and need to perform a perspective transformation in images with these characteristics:

image description

... To look like this:

image description

Researched in various forums, but still did not get results, I heard that the characteristics of a chessboard help in rectifying / transformation of the image. Would appreciate it very much if someone help me at least with step by step. Thank U!

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Comments

Have a look at this: calibration

Abhishek Kumar Annamraju gravatar imageAbhishek Kumar Annamraju ( 2015-02-27 16:05:54 -0500 )edit

Thanks, but i think that this solution not fits on my problem, cause i'm working with a image and this solution is with a camera calibration, with video. Or I can be mistaken. However thanks again!

Sociedade Esportiva Palmeiras gravatar imageSociedade Esportiva Palmeiras ( 2015-02-27 19:05:29 -0500 )edit

is the number of squares of the chessboard considered as known or not, because then you can use the findchessboardcorners() function in combination with this here in order to detect the chessboard easier. Moreover, your input image is distorted, you will need to undistort it first in order to obtain better results.

theodore gravatar imagetheodore ( 2015-02-27 20:36:15 -0500 )edit

Thank you Theodore. I will use a standard chess board, because I will shoot a subject for analysis, on this board, and then perform the transformation on the image, right after this, perform the analysis with the object in a better position.

Sociedade Esportiva Palmeiras gravatar imageSociedade Esportiva Palmeiras ( 2015-02-27 21:38:29 -0500 )edit

Theodore, in this example you gave me, you must find the 4 corners of the chess board, but with the findchessboardcorners are not returned the 4 corners, but is returned something like this: https://uploaddeimagens.com.br/imagen...

Sociedade Esportiva Palmeiras gravatar imageSociedade Esportiva Palmeiras ( 2015-02-27 23:04:03 -0500 )edit

obtaining these corners you can find the four ones that are needed. Moreover, if you want to use a more automatic approach you might try to implement the solution proposed here.

theodore gravatar imagetheodore ( 2015-03-02 09:27:06 -0500 )edit