Add support for alpha weighting to float image.

pull/216/head
castano 16 years ago
parent 2411f3f5db
commit 4f576d5539

@ -12,6 +12,10 @@
#include <math.h>
// This value is to prevent division by zero when weighting kernels by alpha.
#define ALPHA_EPSILON (1.0f / 256.0f)
using namespace nv;
namespace
@ -601,6 +605,15 @@ FloatImage * FloatImage::downSample(const Filter & filter, WrapMode wm) const
return resize(filter, w, h, wm);
}
/// Downsample applying a 1D kernel separately in each dimension.
FloatImage * FloatImage::downSample(const Filter & filter, WrapMode wm, uint alpha) const
{
const uint w = max(1, m_width / 2);
const uint h = max(1, m_height / 2);
return resize(filter, w, h, wm, alpha);
}
/// Downsample applying a 1D kernel separately in each dimension.
FloatImage * FloatImage::resize(const Filter & filter, uint w, uint h, WrapMode wm) const
@ -672,10 +685,51 @@ FloatImage * FloatImage::resize(const Filter & filter, uint w, uint h, WrapMode
return dst_image.release();
}
/// Downsample applying a 1D kernel separately in each dimension.
FloatImage * FloatImage::resize(const Filter & filter, uint w, uint h, WrapMode wm, uint alpha) const
{
nvCheck(alpha < m_componentNum);
AutoPtr<FloatImage> tmp_image( new FloatImage() );
AutoPtr<FloatImage> dst_image( new FloatImage() );
PolyphaseKernel xkernel(filter, m_width, w, 32);
PolyphaseKernel ykernel(filter, m_height, h, 32);
{
tmp_image->allocate(m_componentNum, w, m_height);
dst_image->allocate(m_componentNum, w, h);
Array<float> tmp_column(h);
tmp_column.resize(h);
for (uint c = 0; c < m_componentNum; c++)
{
float * tmp_channel = tmp_image->channel(c);
for (uint y = 0; y < m_height; y++) {
this->applyKernelHorizontal(xkernel, y, c, alpha, wm, tmp_channel + y * w);
}
float * dst_channel = dst_image->channel(c);
for (uint x = 0; x < w; x++) {
tmp_image->applyKernelVertical(ykernel, x, c, alpha, wm, tmp_column.mutableBuffer());
for (uint y = 0; y < h; y++) {
dst_channel[y * w + x] = tmp_column[y];
}
}
}
}
return dst_image.release();
}
/// Apply 2D kernel at the given coordinates and return result.
float FloatImage::applyKernel(const Kernel2 * k, int x, int y, int c, WrapMode wm) const
float FloatImage::applyKernel(const Kernel2 * k, int x, int y, uint c, WrapMode wm) const
{
nvDebugCheck(k != NULL);
@ -704,7 +758,7 @@ float FloatImage::applyKernel(const Kernel2 * k, int x, int y, int c, WrapMode w
/// Apply 1D vertical kernel at the given coordinates and return result.
float FloatImage::applyKernelVertical(const Kernel1 * k, int x, int y, int c, WrapMode wm) const
float FloatImage::applyKernelVertical(const Kernel1 * k, int x, int y, uint c, WrapMode wm) const
{
nvDebugCheck(k != NULL);
@ -726,7 +780,7 @@ float FloatImage::applyKernelVertical(const Kernel1 * k, int x, int y, int c, Wr
}
/// Apply 1D horizontal kernel at the given coordinates and return result.
float FloatImage::applyKernelHorizontal(const Kernel1 * k, int x, int y, int c, WrapMode wm) const
float FloatImage::applyKernelHorizontal(const Kernel1 * k, int x, int y, uint c, WrapMode wm) const
{
nvDebugCheck(k != NULL);
@ -749,7 +803,7 @@ float FloatImage::applyKernelHorizontal(const Kernel1 * k, int x, int y, int c,
/// Apply 1D vertical kernel at the given coordinates and return result.
void FloatImage::applyKernelVertical(const PolyphaseKernel & k, int x, int c, WrapMode wm, float * output) const
void FloatImage::applyKernelVertical(const PolyphaseKernel & k, int x, uint c, WrapMode wm, float * output) const
{
const uint length = k.length();
const float scale = float(length) / float(m_height);
@ -781,7 +835,7 @@ void FloatImage::applyKernelVertical(const PolyphaseKernel & k, int x, int c, Wr
}
/// Apply 1D horizontal kernel at the given coordinates and return result.
void FloatImage::applyKernelHorizontal(const PolyphaseKernel & k, int y, int c, WrapMode wm, float * output) const
void FloatImage::applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, WrapMode wm, float * output) const
{
const uint length = k.length();
const float scale = float(length) / float(m_width);
@ -812,6 +866,79 @@ void FloatImage::applyKernelHorizontal(const PolyphaseKernel & k, int y, int c,
}
}
/// Apply 1D vertical kernel at the given coordinates and return result.
void FloatImage::applyKernelVertical(const PolyphaseKernel & k, int x, uint c, uint a, WrapMode wm, float * output) const
{
const uint length = k.length();
const float scale = float(length) / float(m_height);
const float iscale = 1.0f / scale;
const float width = k.width();
const int windowSize = k.windowSize();
const float * channel = this->channel(c);
const float * alpha = this->channel(a);
for (uint i = 0; i < length; i++)
{
const float center = (0.5f + i) * iscale;
const int left = (int)floorf(center - width);
const int right = (int)ceilf(center + width);
nvCheck(right - left <= windowSize);
float alphaSum = 0;
float sum = 0;
for (int j = 0; j < windowSize; ++j)
{
const int idx = this->index(x, j+left, wm);
float alphaFactor = alpha[idx] + ALPHA_EPSILON;
alphaSum += alphaFactor;
sum += k.valueAt(i, j) * channel[idx] * alphaFactor;
}
output[i] = sum / alphaSum;
}
}
/// Apply 1D horizontal kernel at the given coordinates and return result.
void FloatImage::applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, uint a, WrapMode wm, float * output) const
{
const uint length = k.length();
const float scale = float(length) / float(m_width);
const float iscale = 1.0f / scale;
const float width = k.width();
const int windowSize = k.windowSize();
const float * channel = this->channel(c);
const float * alpha = this->channel(a);
for (uint i = 0; i < length; i++)
{
const float center = (0.5f + i) * iscale;
const int left = (int)floorf(center - width);
const int right = (int)ceilf(center + width);
nvDebugCheck(right - left <= windowSize);
float alphaSum = 0.0f;
float sum = 0;
for (int j = 0; j < windowSize; ++j)
{
const int idx = this->index(left + j, y, wm);
float alphaFactor = alpha[idx] + ALPHA_EPSILON;
alphaSum += alphaFactor;
sum += k.valueAt(i, j) * channel[idx] * alphaFactor;
}
output[i] = sum / alphaSum;
}
}
FloatImage* FloatImage::clone() const
{
FloatImage* copy = new FloatImage();

@ -73,17 +73,21 @@ public:
NVIMAGE_API FloatImage * fastDownSample() const;
NVIMAGE_API FloatImage * downSample(const Filter & filter, WrapMode wm) const;
NVIMAGE_API FloatImage * downSample(const Filter & filter, WrapMode wm, uint alpha) const;
NVIMAGE_API FloatImage * resize(const Filter & filter, uint w, uint h, WrapMode wm) const;
NVIMAGE_API FloatImage * resize(const Filter & filter, uint w, uint h, WrapMode wm, uint alpha) const;
//NVIMAGE_API FloatImage * downSample(const Kernel1 & filter, WrapMode wm) const;
//NVIMAGE_API FloatImage * downSample(const Kernel1 & filter, uint w, uint h, WrapMode wm) const;
//@}
NVIMAGE_API float applyKernel(const Kernel2 * k, int x, int y, int c, WrapMode wm) const;
NVIMAGE_API float applyKernelVertical(const Kernel1 * k, int x, int y, int c, WrapMode wm) const;
NVIMAGE_API float applyKernelHorizontal(const Kernel1 * k, int x, int y, int c, WrapMode wm) const;
NVIMAGE_API void applyKernelVertical(const PolyphaseKernel & k, int x, int c, WrapMode wm, float * output) const;
NVIMAGE_API void applyKernelHorizontal(const PolyphaseKernel & k, int y, int c, WrapMode wm, float * output) const;
NVIMAGE_API float applyKernel(const Kernel2 * k, int x, int y, uint c, WrapMode wm) const;
NVIMAGE_API float applyKernelVertical(const Kernel1 * k, int x, int y, uint c, WrapMode wm) const;
NVIMAGE_API float applyKernelHorizontal(const Kernel1 * k, int x, int y, uint c, WrapMode wm) const;
NVIMAGE_API void applyKernelVertical(const PolyphaseKernel & k, int x, uint c, WrapMode wm, float * output) const;
NVIMAGE_API void applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, WrapMode wm, float * output) const;
NVIMAGE_API void applyKernelVertical(const PolyphaseKernel & k, int x, uint c, uint a, WrapMode wm, float * output) const;
NVIMAGE_API void applyKernelHorizontal(const PolyphaseKernel & k, int y, uint c, uint a, WrapMode wm, float * output) const;
uint width() const { return m_width; }

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