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Xiang_Ma
Beginner
71 Views

How to correctly use ippiRotate to get expected result

I need to rotate an imagewhich is 16 bitswith a w/h. After rotation, the new rotated image should have bigger size. say (w+ deltaW)/(h+deltaH).

I found it only work correctly for some size images (say 640x512), but not correct for other size image- image is distorted a lot.

Following is my code. Thanks very much for any help to find what is wrong on this code.


void Rotate(
unsigned short *pInputImage,
int m_iImage_width,
int m_iImage_height,
double angle,
bool bKeepOrigiImageSize,
unsigned short *& pRotatedImage, // rotated image
int & rImage_Width, // rotated image width
int &rImage_Height, // rotated image height
int iInterpolationMethod)

{

double xShift= 0;

double yShift= 0;

double xCenterSrc = m_iImage_width/2.0;

double yCenterSrc = m_iImage_height/2.0;

double bound[2][2];

IppStatus Status;

int srcStep_16u= 0;

int desStep_16u =0;

IppiSize srcSize = { m_iImage_width, m_iImage_height };

IppiRect srcRect = { 0, 0, m_iImage_width, m_iImage_height };

// find rotate shift

Status = ippiGetRotateShift ( xCenterSrc, yCenterSrc, angle, &xShift, &yShift );

// find rotated boundary box

Status = ippiGetRotateBound ( srcRect, bound, angle, xShift, yShift);

double xTotalShift = xShift;

double yTotalShift = yShift;

if ( !bKeepOrigiImageSize)

{

rImage_Width = bound[1][0] - bound[0][0]+1;

rImage_Height = bound[1][1] - bound[0][1]+1;

xTotalShift = xTotalShift - bound[0][0];

yTotalShift = yTotalShift - bound[0][1];

}

else

{

rImage_Width = m_iImage_width;

rImage_Height = m_iImage_height;

}

IppiRect dstRect = { 0,0, rImage_Width , rImage_Height };

IppiSize dstSize = { rImage_Width, rImage_Height};

// allocate memory

Ipp16u *pIpp16Images = ippiMalloc_16u_C1(m_iImage_width, m_iImage_height, &srcStep_16u);
// Where I should use srcStep_16u?

Ipp16u *pIpp16Imaged = ippiMalloc_16u_C1(rImage_Width , rImage_Height, &desStep_16u);

// Where I should use desStep_16u?

Status = ippiSet_16u_C1R(0, pIpp16Imaged, desStep_16u, dstSize);

// should I use memcpy or ippiCopy_16u_C1R?

memcpy(pIpp16Images,pInputImage,m_iImage_width* m_iImage_height*sizeof(Ipp16u));

Status = ippiRotate_16u_C1R(pIpp16Images, srcSize, 2*m_iImage_width, srcRect, pIpp16Imaged, 2*(rImage_Width), dstRect, angle, xTotalShift, yTotalShift, iInterpolationMethod);

pRotatedImage = new unsigned short[rImage_Width * rImage_Height];

memcpy(pRotatedImage,pIpp16Imaged,rImage_Width * rImage_Height*sizeof(unsigned short));

ippiFree(pIpp16Images);

ippiFree(pIpp16Imaged);

}

0 Kudos
1 Reply
Chao_Y_Intel
Employee
71 Views


Hello,

The image step does not look correct in the code.


Change:
memcpy(pIpp16Images,pInputImage,m_iImage_width* m_iImage_height*sizeof(Ipp16u));

Status = ippiRotate_16u_C1R(pIpp16Images, srcSize, 2*m_iImage_width, srcRect, pIpp16Imaged, 2*(rImage_Width), dstRect, angle, xTotalShift, yTotalShift, iInterpolationMethod);

memcpy(pRotatedImage,pIpp16Imaged,rImage_Width * rImage_Height*sizeof(unsigned short));

to the followngs:
ippiCopy_16u_C1R( pInputImage, m_iImage_width*sizeof(Ipp16u), pIpp16Images, srcStep_16u, srcSize);

Status = ippiRotate_16u_C1R(pIpp16Images, srcSize, srcStep_16u, srcRect, pIpp16Imaged, desStep_16u, dstRect, angle, xTotalShift, yTotalShift, iInterpolationMethod);

ippiCopy_16u_C1R( pIpp16Imaged, desStep_16u, pRotatedImage, rImage_Width*sizeof(unsigned short), dstSize);

The article may provide more information on this problem.

http://software.intel.com/sites/products/documentation/hpc/ipp/ippi/ippi_ch2/ch2_regions_of_interest...

Thanks,
Chao

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