warpPerspective height adjustment

asked 2014-08-01 12:56:44 -0500

jfix gravatar image

I'm creating a bird's eye view using warpPerspective() by following example 12-1 in "Learning OpenCV" by Bradski & Kaehler (The same example is readily found online as well). In the example they allow the user to adjust the "height" by changing a value in the homography matrix. However, the problem I'm having is that the effect of changing this variable is counter intuitive to adjusting the actually height of the "bird" in the bird's eye view. That is, at a height of 25 the resulting view appears closer to the ground (therefore, larger) then at a height of 10. Also, in some cases, negative numbers produce acceptable views. Am I not understanding what the "height" variable is supposed to do or do I have something else wrong?

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Comments

Strangely, in may case only scales the image if i change the height. But I have issues with the mapping to. If you are familiar with the subject can you have a look on my [post]{http://answers.opencv.org/question/43752/bird-eye-view-homography/}

zweistein666 gravatar imagezweistein666 ( 2014-10-07 07:18:10 -0500 )edit