我尝试为warpPerspective()函数指定与基本(0,0)不同的原点，以便独立于支持图像的大小来应用变换。我在原始代码中添加了CvPoint参数，但是找不到在哪里使用这些坐标。我试图在X0，Y0和W0的计算中使用它们，但是它不起作用，这只会在结果图像中移动转换后的图像。任何的想法？
这里的代码:
void warpPerspective( const Mat& src, Mat& dst, const Mat& M0, Size dsize,
int flags, int borderType, const Scalar& borderValue, CvPoint origin )
{
dst.create( dsize, src.type() );
const int BLOCK_SZ = 32;
short XY[BLOCK_SZ*BLOCK_SZ*2], A[BLOCK_SZ*BLOCK_SZ];
double M[9];
Mat _M(3, 3, CV_64F, M);
int interpolation = flags & INTER_MAX;
if( interpolation == INTER_AREA )
interpolation = INTER_LINEAR;
CV_Assert( (M0.type() == CV_32F || M0.type() == CV_64F) && M0.rows == 3 && M0.cols == 3 );
M0.convertTo(_M, _M.type());
if( !(flags & WARP_INVERSE_MAP) )
invert(_M, _M);
int x, y, x1, y1, width = dst.cols, height = dst.rows;
int bh0 = std::min(BLOCK_SZ/2, height);
int bw0 = std::min(BLOCK_SZ*BLOCK_SZ/bh0, width);
bh0 = std::min(BLOCK_SZ*BLOCK_SZ/bw0, height);
for( y = 0; y < height; y += bh0 )
{
for( x = 0; x < width; x += bw0 )
{
int bw = std::min( bw0, width - x);
int bh = std::min( bh0, height - y);
Mat _XY(bh, bw, CV_16SC2, XY), _A;
Mat dpart(dst, Rect(x, y, bw, bh));
for( y1 = 0; y1 < bh; y1++ )
{
short* xy = XY + y1*bw*2;
double X0 = M[0]*x + M[1]*(y + y1) + M[2];
double Y0 = M[3]*x + M[4]*(y + y1) + M[5];
double W0 = M[6]*x + M[7]*(y + y1) + M[8];
if( interpolation == INTER_NEAREST )
for( x1 = 0; x1 < bw; x1++ )
{
double W = W0 + M[6]*x1;
W = W ? 1./W : 0;
int X = saturate_cast<int>((X0 + M[0]*x1)*W);
int Y = saturate_cast<int>((Y0 + M[3]*x1)*W);
xy[x1*2] = (short)X;
xy[x1*2+1] = (short)Y;
}
else
{
short* alpha = A + y1*bw;
for( x1 = 0; x1 < bw; x1++ )
{
double W = W0 + M[6]*x1;
W = W ? INTER_TAB_SIZE/W : 0;
int X = saturate_cast<int>((X0 + M[0]*x1)*W);
int Y = saturate_cast<int>((Y0 + M[3]*x1)*W);
xy[x1*2] = (short)(X >> INTER_BITS);
xy[x1*2+1] = (short)(Y >> INTER_BITS);
alpha[x1] = (short)((Y & (INTER_TAB_SIZE-1))*INTER_TAB_SIZE +
(X & (INTER_TAB_SIZE-1)));
}
}
}
if( interpolation == INTER_NEAREST )
remap( src, dpart, _XY, Mat(), interpolation, borderType, borderValue );
else
{
Mat _A(bh, bw, CV_16U, A);
remap( src, dpart, _XY, _A, interpolation, borderType, borderValue );
}
}
}
}
最佳答案
好的，我自己找到了!您有2件事要做:
这是经过转换的代码:
void warpPerspective( const Mat& src, Mat& dst, const Mat& M0, Size dsize,
int flags, int borderType, const Scalar& borderValue, CvPoint origin )
{
dst.create( dsize, src.type() );
const int BLOCK_SZ = 32;
short XY[BLOCK_SZ*BLOCK_SZ*2], A[BLOCK_SZ*BLOCK_SZ];
double M[9];
Mat _M(3, 3, CV_64F, M);
int interpolation = flags & INTER_MAX;
if( interpolation == INTER_AREA )
interpolation = INTER_LINEAR;
CV_Assert( (M0.type() == CV_32F || M0.type() == CV_64F) && M0.rows == 3 && M0.cols == 3 );
M0.convertTo(_M, _M.type());
if( !(flags & WARP_INVERSE_MAP) )
invert(_M, _M);
int x, xDest, y, yDest, x1, y1, width = dst.cols, height = dst.rows;
int bh0 = std::min(BLOCK_SZ/2, height);
int bw0 = std::min(BLOCK_SZ*BLOCK_SZ/bh0, width);
bh0 = std::min(BLOCK_SZ*BLOCK_SZ/bw0, height);
for( y = -origin.y, yDest = 0; y < height; y += bh0, yDest += bh0 )
{
for( x = -origin.x, xDest = 0; x < width; x += bw0, xDest += bw0 )
{
int bw = std::min( bw0, width - x);
int bh = std::min( bh0, height - y);
// to avoid dimensions errors
if (bw <= 0 || bh <= 0)
break;
Mat _XY(bh, bw, CV_16SC2, XY), _A;
Mat dpart(dst, Rect(xDest, yDest, bw, bh));
for( y1 = 0; y1 < bh; y1++ )
{
short* xy = XY + y1*bw*2;
double X0 = M[0]*x + M[1]*(y + y1) + M[2];
double Y0 = M[3]*x + M[4]*(y + y1) + M[5];
double W0 = M[6]*x + M[7]*(y + y1) + M[8];
if( interpolation == INTER_NEAREST )
for( x1 = 0; x1 < bw; x1++ )
{
double W = W0 + M[6]*x1;
W = W ? 1./W : 0;
int X = saturate_cast<int>((X0 + M[0]*x1)*W);
int Y = saturate_cast<int>((Y0 + M[3]*x1)*W);
xy[x1*2] = (short)X;
xy[x1*2+1] = (short)Y;
}
else
{
short* alpha = A + y1*bw;
for( x1 = 0; x1 < bw; x1++ )
{
double W = W0 + M[6]*x1;
W = W ? INTER_TAB_SIZE/W : 0;
int X = saturate_cast<int>((X0 + M[0]*x1)*W);
int Y = saturate_cast<int>((Y0 + M[3]*x1)*W);
xy[x1*2] = (short)(X >> INTER_BITS) + origin.x;
xy[x1*2+1] = (short)(Y >> INTER_BITS) + origin.y;
alpha[x1] = (short)((Y & (INTER_TAB_SIZE-1))*INTER_TAB_SIZE +
(X & (INTER_TAB_SIZE-1)));
}
}
}
if( interpolation == INTER_NEAREST )
remap( src, dpart, _XY, Mat(), interpolation, borderType, borderValue );
else
{
Mat _A(bh, bw, CV_16U, A);
remap( src, dpart, _XY, _A, interpolation, borderType, borderValue );
}
}
}
}
具有此功能:
CvPoint transformPoint(const CvPoint pointToTransform, const CvMat* matrix) {
double coordinates[3] = {pointToTransform.x, pointToTransform.y, 1};
CvMat originVector = cvMat(3, 1, CV_64F, coordinates);
CvMat transformedVector = cvMat(3, 1, CV_64F, coordinates);
cvMatMul(matrix, &originVector, &transformedVector);
CvPoint outputPoint = cvPoint((int)(cvmGet(&transformedVector, 0, 0) / cvmGet(&transformedVector, 2, 0)), (int)(cvmGet(&transformedVector, 1, 0) / cvmGet(&transformedVector, 2, 0)));
return outputPoint;
}
关于opencv - 在OpenCV 2.x中为warpPerspective()函数指定一个原点，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/4279008/