void Convolve(CImageOf<T> src, CImageOf<T>& dst,
CFloatImage kernel)
{
// Determine the shape of the kernel and source image
CShape kShape = kernel.Shape();
CShape sShape = src.Shape();
// Allocate the result, if necessary
dst.ReAllocate(sShape, false);
if (sShape.width * sShape.height * sShape.nBands == 0)
return;
// Do the convolution
for (int y = 0; y < sShape.height; y++)
for (int x = 0; x < sShape.width; x++)
for (int c = 0; c < sShape.nBands; c++)
{
double sum = 0;
for (int kx = 0; kx < kShape.width; kx++)
for (int ky = 0; ky < kShape.height; ky++)
if ((x-kernel.origin[0]+kx >= 0) && (x-kernel.origin[0]+kx < sShape.width) && (y-kernel.origin[1]+ky >= 0) && (y-kernel.origin[1]+ky < sShape.height))
sum += kernel.Pixel(kx,ky,0) * src.Pixel(x-kernel.origin[0]+kx,y-kernel.origin[1]+ky,c);
dst.Pixel(x,y,c) = (T) __max(dst.MinVal(), __min(dst.MaxVal(), sum));
}
}
void WarpGlobal(CImageOf<T> src, CImageOf<T>& dst,
CTransform3x3 M,
EWarpInterpolationMode interp, float cubicA)
{
// Not implemented yet, since haven't decided on semantics of M yet...
// Check that dst is of a valid shape
if (dst.Shape().width == 0)
dst.ReAllocate(src.Shape());
CShape sh = dst.Shape();
// Allocate a row buffer for coordinates
int n = sh.width;
std::vector<float> rowBuf;
rowBuf.resize(n*2);
// Precompute the cubic interpolant
if (interp == eWarpInterpCubic)
InitializeCubicLUT(cubicA);
// Process each row
for (int y = 0; y < sh.height; y++)
{
float *xyP = &rowBuf[0];
T *dstP = &dst.Pixel(0, y, 0);
// Compute pixel coordinates
float X0 = (float) (M[0][1]*y + M[0][2]);
float dX = (float) (M[0][0]);
float Y0 = (float) (M[1][1]*y + M[1][2]);
float dY = (float) (M[1][0]);
float Z0 = (float) (M[2][1]*y + M[2][2]);
float dZ = (float) (M[2][0]);
bool affine = (dZ == 0.0);
float Zi = 1.0f / Z0; // TODO: doesn't guard against divide by 0
if (affine)
{
X0 *= Zi, dX *= Zi, Y0 *= Zi, dY *= Zi;
}
for (int x = 0; x < n; x++)
{
xyP[2*x+0] = X0 * Zi;
xyP[2*x+1] = Y0 * Zi;
X0 += dX;
Y0 += dY;
if (! affine)
{
Z0 += dZ;
Zi = 1.0f / Z0;
}
}
// Resample the line
WarpLine(src, dstP, xyP, n, sh.nBands, interp, src.MinVal(), src.MaxVal());
}
}
void Convolve(CImageOf<T> src, CImageOf<T>& dst,
CFloatImage kernel,
float scale, float offset)
{
// Determine the shape of the kernel and row buffer
CShape kShape = kernel.Shape();
CShape sShape = src.Shape();
CShape bShape(sShape.width + kShape.width, kShape.height, sShape.nBands);
int bWidth = bShape.width * bShape.nBands;
// Allocate the result, if necessary, and the row buffer
dst.ReAllocate(sShape, false);
CFloatImage buffer(bShape);
if (sShape.width * sShape.height * sShape.nBands == 0)
return;
CFloatImage output(CShape(sShape.width, 1, sShape.nBands));
// Fill up the row buffer initially
for (int k = 0; k < kShape.height; k++)
FillRowBuffer(&buffer.Pixel(0, k, 0), src, kernel, k, bWidth);
// Determine if clipping is required
// (we assume up-conversion to float never requires clipping, i.e.,
// floats have the highest dynamic range)
T minVal = dst.MinVal();
T maxVal = dst.MaxVal();
if (minVal <= buffer.MinVal() && maxVal >= buffer.MaxVal())
minVal = maxVal = 0;
// Process each row
for (int y = 0; y < sShape.height; y++)
{
// Do the convolution
ConvolveRow2D(buffer, kernel, &output.Pixel(0, 0, 0),
sShape.width);
// Scale, offset, and type convert
ScaleAndOffsetLine(&output.Pixel(0, 0, 0), &dst.Pixel(0, y, 0),
sShape.width * sShape.nBands,
scale, offset, minVal, maxVal);
// Shift up the row buffer and fill the last line
if (y < sShape.height-1)
{
int k;
for (k = 0; k < kShape.height-1; k++)
memcpy(&buffer.Pixel(0, k, 0), &buffer.Pixel(0, k+1, 0),
bWidth * sizeof(float));
FillRowBuffer(&buffer.Pixel(0, k, 0), src, kernel, y+k+1, bWidth);
}
}
}
void WarpLocal(CImageOf<T> src, CImageOf<T>& dst,
CFloatImage uv, bool relativeCoords,
EWarpInterpolationMode interp, float cubicA)
{
// Check that dst is of the right shape
CShape sh(uv.Shape().width, uv.Shape().height, src.Shape().nBands);
dst.ReAllocate(sh);
// Allocate a row buffer for coordinates
int n = sh.width;
std::vector<float> rowBuf;
rowBuf.resize(n*2);
// Precompute the cubic interpolant
if (interp == eWarpInterpCubic)
InitializeCubicLUT(cubicA);
// Process each row
for (int y = 0; y < sh.height; y++)
{
float *uvP = &uv .Pixel(0, y, 0);
float *xyP = (relativeCoords) ? &rowBuf[0] : uvP;
T *dstP = &dst.Pixel(0, y, 0);
// Convert to absolute coordinates if necessary
if (relativeCoords)
{
for (int x = 0; x < n; x++)
{
xyP[2*x+0] = x + uvP[2*x+0];
xyP[2*x+1] = y + uvP[2*x+1];
}
}
// Resample the line
WarpLine(src, dstP, xyP, n, sh.nBands, interp, src.MinVal(), src.MaxVal());
}
}
extern void ForwardWarp(CImageOf<T>& src, CImageOf<T>& dst, CFloatImage& disp,
float d_scale, bool line_interpolate, float disp_gap)
{
// Warps src into dst using disparities disp.
// Each disparity is scaled by d_scale
// Note that "empty" pixels are left at their original value
CShape sh = src.Shape();
int w = sh.width, h = sh.height, n_bands = sh.nBands;
float round_offset = (typeid(T) == typeid(float)) ? 0.0f : 0.5f;
if (! sh.SameIgnoringNBands(disp.Shape()))
throw CError("ForwardWarp: disparity image has wrong size");
if (sh != dst.Shape())
dst.ReAllocate(sh);
// Optional clipping (if necessary)
CFloatImage flt;
T minVal = dst.MinVal();
T maxVal = dst.MaxVal();
if (minVal <= flt.MinVal() && maxVal >= flt.MaxVal())
minVal = maxVal = 0;
for (int y = 0; y < h; y++)
{
// determine correct warping direction
int xstart = (d_scale>0 ? 0 : w-1);
int xend = (d_scale>0 ? w : -1 );
int xincr = (d_scale>0 ? 1 : -1 );
float *dp = &disp.Pixel(0, y, 0);
T *ps = &src .Pixel(0, y, 0);
T *pd = &dst .Pixel(0, y, 0);
for (int x = xstart; x != xend; x += xincr)
{
// determine if a line should be drawn
int x2 = x + xincr;
float d_diff = fabs(dp[x] - dp[x2]);
bool draw_line = line_interpolate && (x2 != xend) &&
(d_diff < disp_gap);
// scaled disparity:
float d = d_scale * dp[x];
// line drawing
if (draw_line)
{
float d2 = d_scale * dp[x2];
if (xincr > 0)
draw_intensity_line(&ps[x * n_bands], &ps[x2 * n_bands], pd,
x - d, x2 - d2, w, n_bands, round_offset,
minVal, maxVal);
else
draw_intensity_line(&ps[x2 * n_bands], &ps[x * n_bands], pd,
x2 - d, x - d2, w, n_bands, round_offset,
minVal, maxVal);
continue;
}
// splatting
int xx = x - ROUND(d);
if (xx >= 0 && xx < w)
memcpy(&pd[xx * n_bands], &ps[x * n_bands],
n_bands*sizeof(T));
}
}
}
extern void InverseWarp(CImageOf<T>& src, CImageOf<T>& dst, CFloatImage& disp,
float d_scale, float disp_gap, int order)
{
// Warps src into dst using disparities disp.
// Each disparity is scaled by d_scale
// Note that "empty" pixels are left at their original value
CShape sh = src.Shape();
int w = sh.width, h = sh.height, n_bands = sh.nBands;
int n = w * n_bands;
if (! sh.SameIgnoringNBands(disp.Shape()))
throw CError("InverseWarp: disparity image has wrong size");
if (sh != dst.Shape())
dst.ReAllocate(sh);
// Optional forward warped depth map if checking for visibility
CFloatImage fwd, fwd_tmp;
if (disp_gap > 0.0f)
{
ScaleAndOffset(disp, fwd_tmp, d_scale, 0.0f);
fwd.ReAllocate(disp.Shape());
fwd.FillPixels(-9999.0f);
ForwardWarp(fwd_tmp, fwd, disp, d_scale, true, disp_gap);
}
// Allocate line buffers
std::vector<float> src_buf, dst_buf, dsp_buf;
src_buf.resize(n);
dst_buf.resize(n);
dsp_buf.resize(n);
CFloatImage fimg; // dummy, used for MinVal(), MaxVal()
for (int y = 0; y < h; y++)
{
// Set up (copy) the line buffers
ScaleAndOffsetLine(&src .Pixel(0, y, 0), &src_buf[0], n,
1.0f, 0.0f, fimg.MinVal(), fimg.MaxVal());
ScaleAndOffsetLine(&disp.Pixel(0, y, 0), &dsp_buf[0], w,
d_scale, 0.0f, 0.0f, 0.0f);
ScaleAndOffsetLine(&dst .Pixel(0, y, 0), &dst_buf[0], n,
1.0f, 0.0f, fimg.MinVal(), fimg.MaxVal());
// Forward warp the depth map
float *fwd_buf = (disp_gap > 0.0f) ? &fwd.Pixel(0, y, 0) : 0;
// Process (warp) the line
InverseWarpLine(&src_buf[0], &dst_buf[0], &dsp_buf[0],
w, n_bands, order, fwd_buf, disp_gap);
// Convert back to native type
T minVal = dst.MinVal();
T maxVal = dst.MaxVal();
float offset = (typeid(T) == typeid(float)) ? 0.0f : 0.5; // rounding
if (minVal <= fimg.MinVal() && maxVal >= fimg.MaxVal())
minVal = maxVal = 0;
ScaleAndOffsetLine(&dst_buf[0], &dst.Pixel(0, y, 0), n,
1.0f, offset, minVal, maxVal);
}
}
