topic Error code ippStsCoeffErr with ippiWarpPerspective in Intel® Integrated Performance Primitives

Error code ippStsCoeffErr with ippiWarpPerspective

Scott_Mcmichael — Wed, 25 May 2011 18:02:58 GMT

I am trying to use ippiWarpPerspective and get error code -56 (ippStsCoeffErr) when I pass in non-identity transforms. I found some old threads about this issue but no solutions:

http://origin-software.intel.com/en-us/forums/showthread.php?t=63339
http://software.intel.com/en-us/forums/showthread.php?t=54250&o=a&s=lr&wapkw=%28Architecture+Software+Developer%29

Here is a sample coefficient set that I am passing in to the function as reported by visual studio:

[0][0] 0.99999426951673498
[0][1] -3.0119434616414690e-006
[0][2] 1.9780879024589358e-008
[1][0] 0.00023626541131144098
[1][1] 0.99993458569317439
[1][2] 1.2301679847236111e-007
[2][0] -0.040422124313244316
[2][1] 0.0062414088928023541
[2][2] 1.0

I am pretty sure all the other function inputs are correct since they work with the identity transform. Are there any unstated reqirements of this function that my coefficients violate?

Error code ippStsCoeffErr with ippiWarpPerspective

Chao_Y_Intel — Fri, 27 May 2011 09:49:38 GMT

Hello,

We noticed one related problem reported before. The problem happens because the following check error:

Before transform we need to check the quad polygon convexity and orientation.
double area0 = (quad[3][0] - quad[2][0]) * (quad[0][1] - quad[3][1]) (quad[0][0] - quad[3][0]) * (quad[3][1] - quad[2][1]);
double area1 = (quad[0][0] - quad[3][0]) * (quad[1][1] - quad[0][1]) (quad[1][0] - quad[0][0]) * (quad[0][1] - quad[3][1]);
double area2 = (quad[1][0] - quad[0][0]) * (quad[2][1] - quad[1][1]) (quad[2][0] - quad[1][0]) * (quad[1][1] - quad[0][1]);
double area3 = (quad[2][0] - quad[1][0]) * (quad[3][1] - quad[2][1]) (quad[3][0] - quad[2][0]) * (quad[2][1] - quad[1][1]);

If area0, area1, area2, area3 have different signs that means the specified rectangle is non-convex. Is this problem for your case?

Thanks,
Chao

Error code ippStsCoeffErr with ippiWarpPerspective

Scott_Mcmichael — Wed, 01 Jun 2011 16:33:20 GMT

I don't think it would affect us if the rectangle is non-convex. We are just trying to compute an approximate transform between two successive images from a video camera.

I guess the way to work around this would be to compute all of the pixel locations manually and then pass them to the IPP remap function but I imagine that will be much slower than the single function call would be.

Scott