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nvidia-texture-tools/trunk/src/nvimage/FloatImage.cpp

840 lines
22 KiB
C++

// This code is in the public domain -- castanyo@yahoo.es
#include <nvcore/Containers.h>
#include <nvcore/Ptr.h>
#include <nvmath/Color.h>
#include "FloatImage.h"
#include "Filter.h"
#include "Image.h"
#include <math.h>
using namespace nv;
namespace
{
static int round(float f)
{
return int(f);
}
static float frac(float f)
{
return f - floor(f);
}
}
/// Ctor.
FloatImage::FloatImage() : m_width(0), m_height(0),
m_componentNum(0), m_count(0), m_mem(NULL)
{
}
/// Ctor. Init from image.
FloatImage::FloatImage(const Image * img) : m_width(0), m_height(0),
m_componentNum(0), m_count(0), m_mem(NULL)
{
initFrom(img);
}
/// Dtor.
FloatImage::~FloatImage()
{
free();
}
/// Init the floating point image from a regular image.
void FloatImage::initFrom(const Image * img)
{
nvCheck(img != NULL);
allocate(4, img->width(), img->height());
float * red_channel = channel(0);
float * green_channel = channel(1);
float * blue_channel = channel(2);
float * alpha_channel = channel(3);
const uint count = m_width * m_height;
for(uint i = 0; i < count; i++) {
Color32 pixel = img->pixel(i);
red_channel[i] = float(pixel.r) / 255.0f;
green_channel[i] = float(pixel.g) / 255.0f;
blue_channel[i] = float(pixel.b) / 255.0f;
alpha_channel[i] = float(pixel.a) / 255.0f;
}
}
/// Convert the floating point image to a regular image.
Image * FloatImage::createImage(uint base_component/*= 0*/, uint num/*= 4*/) const
{
nvCheck(num <= 4);
nvCheck(base_component + num <= m_componentNum);
AutoPtr<Image> img(new Image());
img->allocate(m_width, m_height);
const uint size = m_width * m_height;
for(uint i = 0; i < size; i++) {
uint c;
uint8 rgba[4];
for(c = 0; c < num; c++) {
float f = m_mem[size * (base_component + c) + i];
rgba[c] = nv::clamp(int(255.0f * f), 0, 255);
}
// Fill the rest with 0xff000000;
for(; c < 4; c++) {
rgba[c] = c != 3 ? 0 : 0xff;
}
img->pixel(i) = Color32(rgba[0], rgba[1], rgba[2], rgba[3]);
}
return img.release();
}
/// Convert the floating point image to a regular image. Correct gamma of rgb, but not alpha.
Image * FloatImage::createImageGammaCorrect(float gamma/*= 2.2f*/) const
{
nvCheck(m_componentNum == 4);
AutoPtr<Image> img(new Image());
img->allocate(m_width, m_height);
const float * rChannel = this->channel(0);
const float * gChannel = this->channel(1);
const float * bChannel = this->channel(2);
const float * aChannel = this->channel(3);
const uint size = m_width * m_height;
for(uint i = 0; i < size; i++)
{
const uint8 r = nv::clamp(int(255.0f * pow(rChannel[i], 1.0f/gamma)), 0, 255);
const uint8 g = nv::clamp(int(255.0f * pow(gChannel[i], 1.0f/gamma)), 0, 255);
const uint8 b = nv::clamp(int(255.0f * pow(bChannel[i], 1.0f/gamma)), 0, 255);
const uint8 a = nv::clamp(int(255.0f * aChannel[i]), 0, 255);
img->pixel(i) = Color32(r, g, b, a);
}
return img.release();
}
/// Allocate a 2d float image of the given format and the given extents.
void FloatImage::allocate(uint c, uint w, uint h)
{
nvCheck(m_mem == NULL);
m_width = w;
m_height = h;
m_componentNum = c;
m_count = w * h * c;
m_mem = reinterpret_cast<float *>(nv::mem::malloc(m_count * sizeof(float)));
}
/// Free the image, but don't clear the members.
void FloatImage::free()
{
nvCheck(m_mem != NULL);
nv::mem::free( reinterpret_cast<void *>(m_mem) );
m_mem = NULL;
}
void FloatImage::clear(float f/*=0.0f*/)
{
for(uint i = 0; i < m_count; i++) {
m_mem[i] = f;
}
}
void FloatImage::normalize(uint base_component)
{
nvCheck(base_component + 3 <= m_componentNum);
float * xChannel = this->channel(base_component + 0);
float * yChannel = this->channel(base_component + 1);
float * zChannel = this->channel(base_component + 2);
const uint size = m_width * m_height;
for(uint i = 0; i < size; i++) {
Vector3 normal(xChannel[i], yChannel[i], zChannel[i]);
normal = normalizeSafe(normal, Vector3(zero));
xChannel[i] = normal.x();
yChannel[i] = normal.y();
zChannel[i] = normal.z();
}
}
void FloatImage::packNormals(uint base_component)
{
scaleBias(base_component, 3, 0.5f, 1.0f);
}
void FloatImage::expandNormals(uint base_component)
{
scaleBias(base_component, 3, 2, -0.5);
}
void FloatImage::scaleBias(uint base_component, uint num, float scale, float bias)
{
const uint size = m_width * m_height;
for(uint c = 0; c < num; c++) {
float * ptr = this->channel(base_component + c);
for(uint i = 0; i < size; i++) {
ptr[i] = scale * (ptr[i] + bias);
}
}
}
/// Clamp the elements of the image.
void FloatImage::clamp(float low, float high)
{
for(uint i = 0; i < m_count; i++) {
m_mem[i] = nv::clamp(m_mem[i], low, high);
}
}
/// From gamma to linear space.
void FloatImage::toLinear(uint base_component, uint num, float gamma /*= 2.2f*/)
{
exponentiate(base_component, num, gamma);
}
/// From linear to gamma space.
void FloatImage::toGamma(uint base_component, uint num, float gamma /*= 2.2f*/)
{
exponentiate(base_component, num, 1.0f/gamma);
}
/// Exponentiate the elements of the image.
void FloatImage::exponentiate(uint base_component, uint num, float power)
{
const uint size = m_width * m_height;
for(uint c = 0; c < num; c++) {
float * ptr = this->channel(base_component + c);
for(uint i = 0; i < size; i++) {
ptr[i] = pow(ptr[i], power);
}
}
}
#if 0
float FloatImage::nearest(float x, float y, int c, WrapMode wm) const
{
if( wm == WrapMode_Clamp ) return nearest_clamp(x, y, c);
/*if( wm == WrapMode_Repeat )*/ return nearest_repeat(x, y, c);
//if( wm == WrapMode_Mirror ) return nearest_mirror(x, y, c);
}
float FloatImage::nearest_clamp(int x, int y, const int c) const
{
const int w = m_width;
const int h = m_height;
int ix = ::clamp(x, 0, w-1);
int iy = ::clamp(y, 0, h-1);
return pixel(ix, iy, c);
}
float FloatImage::nearest_repeat(int x, int y, const int c) const
{
const int w = m_width;
const int h = m_height;
int ix = x % w;
int iy = y % h;
return pixel(ix, iy, c);
}
#endif
float FloatImage::nearest(float x, float y, int c, WrapMode wm) const
{
if( wm == WrapMode_Clamp ) return nearest_clamp(x, y, c);
/*if( wm == WrapMode_Repeat )*/ return nearest_repeat(x, y, c);
//if( wm == WrapMode_Mirror ) return nearest_mirror(x, y, c);
}
float FloatImage::linear(float x, float y, int c, WrapMode wm) const
{
if( wm == WrapMode_Clamp ) return linear_clamp(x, y, c);
/*if( wm == WrapMode_Repeat )*/ return linear_repeat(x, y, c);
//if( wm == WrapMode_Mirror ) return linear_mirror(x, y, c);
}
float FloatImage::nearest_clamp(float x, float y, const int c) const
{
const int w = m_width;
const int h = m_height;
int ix = ::clamp(round(x * w), 0, w-1);
int iy = ::clamp(round(y * h), 0, h-1);
return pixel(ix, iy, c);
}
float FloatImage::nearest_repeat(float x, float y, const int c) const
{
const int w = m_width;
const int h = m_height;
int ix = round(frac(x) * w);
int iy = round(frac(y) * h);
return pixel(ix, iy, c);
}
float FloatImage::nearest_mirror(float x, float y, const int c) const
{
// @@ TBD
return 0.0f;
}
float FloatImage::linear_clamp(float x, float y, const int c) const
{
const int w = m_width;
const int h = m_height;
x *= w;
y *= h;
const float fracX = frac(x);
const float fracY = frac(y);
const int ix0 = ::clamp(round(x), 0, w-1);
const int iy0 = ::clamp(round(y), 0, h-1);
const int ix1 = ::clamp(round(x)+1, 0, w-1);
const int iy1 = ::clamp(round(y)+1, 0, h-1);
float f1 = pixel(ix0, iy0, c);
float f2 = pixel(ix1, iy0, c);
float f3 = pixel(ix0, iy1, c);
float f4 = pixel(ix1, iy1, c);
float i1 = lerp(f1, f2, fracX);
float i2 = lerp(f3, f4, fracX);
return lerp(i1, i2, fracY);
}
float FloatImage::linear_repeat(float x, float y, int c) const
{
const int w = m_width;
const int h = m_height;
const float fracX = frac(x * w);
const float fracY = frac(y * h);
int ix0 = round(frac(x) * w);
int iy0 = round(frac(y) * h);
int ix1 = round(frac(x + 1.0f/w) * w);
int iy1 = round(frac(y + 1.0f/h) * h);
float f1 = pixel(ix0, iy0, c);
float f2 = pixel(ix1, iy0, c);
float f3 = pixel(ix0, iy1, c);
float f4 = pixel(ix1, iy1, c);
float i1 = lerp(f1, f2, fracX);
float i2 = lerp(f3, f4, fracX);
return lerp(i1, i2, fracY);
}
float FloatImage::linear_mirror(float x, float y, int c) const
{
// @@ TBD
return 0.0f;
}
/// Fast downsampling using box filter.
///
/// The extents of the image are divided by two and rounded down.
///
/// When the size of the image is odd, this uses a polyphase box filter as explained in:
/// http://developer.nvidia.com/object/np2_mipmapping.html
///
FloatImage * FloatImage::fastDownSample() const
{
nvDebugCheck(m_width != 1 || m_height != 1);
AutoPtr<FloatImage> dst_image( new FloatImage() );
const uint w = max(1, m_width / 2);
const uint h = max(1, m_height / 2);
dst_image->allocate(m_componentNum, w, h);
// 1D box filter.
if (m_width == 1 || m_height == 1)
{
const uint w = m_width * m_height;
if (w & 1)
{
const float scale = 1.0f / (2 * w + 1);
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint x = 0; x < w; x++)
{
const float w0 = (w - x);
const float w1 = (w - 0);
const float w2 = (1 + x);
*dst++ = scale * (w0 * src[0] + w1 * src[1] + w2 * src[2]);
src += 2;
}
}
}
else
{
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint x = 0; x < w; x++)
{
*dst = 0.5f * (src[0] + src[1]);
dst++;
src += 2;
}
}
}
}
// Regular box filter.
else if ((m_width & 1) == 0 && (m_height & 1) == 0)
{
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint y = 0; y < h; y++)
{
for(uint x = 0; x < w; x++)
{
*dst = 0.25f * (src[0] + src[1] + src[m_width] + src[m_width + 1]);
dst++;
src += 2;
}
src += m_width;
}
}
}
// Polyphase filters.
else if (m_width & 1 && m_height & 1)
{
nvDebugCheck(m_width == 2 * w + 1);
nvDebugCheck(m_height == 2 * h + 1);
const float scale = 1.0f / (m_width * m_height);
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint y = 0; y < h; y++)
{
const float v0 = (h - y);
const float v1 = (h - 0);
const float v2 = (1 + y);
for (uint x = 0; x < w; x++)
{
const float w0 = (w - x);
const float w1 = (w - 0);
const float w2 = (1 + x);
float f = 0.0f;
f += v0 * (w0 * src[0 * m_width + 2 * x] + w1 * src[0 * m_width + 2 * x + 1] + w2 * src[0 * m_width + 2 * x + 2]);
f += v1 * (w0 * src[1 * m_width + 2 * x] + w1 * src[1 * m_width + 2 * x + 1] + w2 * src[0 * m_width + 2 * x + 2]);
f += v2 * (w0 * src[2 * m_width + 2 * x] + w1 * src[2 * m_width + 2 * x + 1] + w2 * src[0 * m_width + 2 * x + 2]);
*dst = f * scale;
dst++;
}
src += 2 * m_width;
}
}
}
else if (m_width & 1)
{
nvDebugCheck(m_width == 2 * w + 1);
const float scale = 1.0f / (2 * m_width);
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint y = 0; y < h; y++)
{
for (uint x = 0; x < w; x++)
{
const float w0 = (w - x);
const float w1 = (w - 0);
const float w2 = (1 + x);
float f = 0.0f;
f += w0 * (src[2 * x + 0] + src[m_width + 2 * x + 0]);
f += w1 * (src[2 * x + 1] + src[m_width + 2 * x + 1]);
f += w2 * (src[2 * x + 2] + src[m_width + 2 * x + 2]);
*dst = f * scale;
dst++;
}
src += 2 * m_width;
}
}
}
else if (m_height & 1)
{
nvDebugCheck(m_height == 2 * h + 1);
const float scale = 1.0f / (2 * m_height);
for(uint c = 0; c < m_componentNum; c++)
{
const float * src = this->channel(c);
float * dst = dst_image->channel(c);
for(uint y = 0; y < h; y++)
{
const float v0 = (h - y);
const float v1 = (h - 0);
const float v2 = (1 + y);
for (uint x = 0; x < w; x++)
{
float f = 0.0f;
f += v0 * (src[0 * m_width + 2 * x] + src[0 * m_width + 2 * x + 1]);
f += v1 * (src[1 * m_width + 2 * x] + src[1 * m_width + 2 * x + 1]);
f += v2 * (src[2 * m_width + 2 * x] + src[2 * m_width + 2 * x + 1]);
*dst = f * scale;
dst++;
}
src += 2 * m_width;
}
}
}
return dst_image.release();
}
/// Downsample applying a 1D kernel separately in each dimension.
FloatImage * FloatImage::downSample(const Kernel1 & kernel, WrapMode wm) const
{
const uint w = max(1, m_width / 2);
const uint h = max(1, m_height / 2);
return downSample(kernel, w, h, wm);
}
/// Downsample applying a 1D kernel separately in each dimension.
FloatImage * FloatImage::downSample(const Kernel1 & kernel, uint w, uint h, WrapMode wm) const
{
nvCheck(!(kernel.width() & 1)); // Make sure that kernel m_width is even.
AutoPtr<FloatImage> tmp_image( new FloatImage() );
tmp_image->allocate(m_componentNum, w, m_height);
AutoPtr<FloatImage> dst_image( new FloatImage() );
dst_image->allocate(m_componentNum, w, h);
const float xscale = float(m_width) / float(w);
const float yscale = float(m_height) / float(h);
for(uint c = 0; c < m_componentNum; c++) {
float * tmp_channel = tmp_image->channel(c);
for(uint y = 0; y < m_height; y++) {
for(uint x = 0; x < w; x++) {
float sum = this->applyKernelHorizontal(&kernel, uint(x*xscale), y, c, wm);
const uint tmp_index = tmp_image->index(x, y);
tmp_channel[tmp_index] = sum;
}
}
float * dst_channel = dst_image->channel(c);
for(uint y = 0; y < h; y++) {
for(uint x = 0; x < w; x++) {
float sum = this->applyKernelVertical(&kernel, uint(x*xscale), uint(y*yscale), c, wm);
const uint dst_index = dst_image->index(x, y);
dst_channel[dst_index] = sum;
}
}
}
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
{
nvDebugCheck(k != NULL);
const uint kernelWidth = k->width();
const int kernelOffset = int(kernelWidth / 2) - 1;
const float * channel = this->channel(c);
float sum = 0.0f;
for(uint i = 0; i < kernelWidth; i++)
{
const int src_y = int(y + i) - kernelOffset;
for(uint e = 0; e < kernelWidth; e++)
{
const int src_x = int(x + e) - kernelOffset;
int idx = this->index(src_x, src_y, wm);
sum += k->valueAt(e, i) * channel[idx];
}
}
return sum;
}
/// 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
{
nvDebugCheck(k != NULL);
const uint kernelWidth = k->width();
const int kernelOffset = int(kernelWidth / 2) - 1;
const float * channel = this->channel(c);
float sum = 0.0f;
for(uint i = 0; i < kernelWidth; i++)
{
const int src_y = int(y + i) - kernelOffset;
const int idx = this->index(x, src_y, wm);
sum += k->valueAt(i) * channel[idx];
}
return sum;
}
/// 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
{
nvDebugCheck(k != NULL);
const uint kernelWidth = k->width();
const int kernelOffset = int(kernelWidth / 2) - 1;
const float * channel = this->channel(c);
float sum = 0.0f;
for(uint e = 0; e < kernelWidth; e++)
{
const int src_x = int(x + e) - kernelOffset;
const int idx = this->index(src_x, y, wm);
sum += k->valueAt(e) * channel[idx];
}
return sum;
}
#if 0
Vec3d bilinear(double u, double v) const
{
u = mod(u*(W-1),W);
v = mod(v*(H-1),H);
Vec3d v1,v2,v3,v4;
int x_small = (int)floor(u);
int x_big = x_small + 1;
int y_small = (int)floor(v);
int y_big = y_small + 1;
if (x_small < 0)
x_small = W-1;
else if (x_big >= W)
x_big = 0;
if (y_small < 0)
y_small = H-1;
else if (y_big >= H)
y_big = 0;
double fractional_X = u - x_small;
double fractional_Y = v - y_small;
if (nchan == 3)
{
v1 = Vec3d(pixel(x_small, y_small)[0], pixel(x_small, y_small)[1], pixel(x_small, y_small)[2]);
v2 = Vec3d(pixel(x_big, y_small)[0], pixel(x_big, y_small)[1], pixel(x_big, y_small)[2]);
v3 = Vec3d(pixel(x_small, y_big)[0], pixel(x_small, y_big)[1], pixel(x_small, y_big)[2]);
v4 = Vec3d(pixel(x_big, y_big)[0], pixel(x_big, y_big)[1], pixel(x_big, y_big)[2]);
}
Vec3d i1 = lerp(v1, v2, fractional_X);
Vec3d i2 = lerp(v3, v4, fractional_X);
return lerp(i1, i2, fractional_Y);
}
Vec3d bicubic(double u, double v) const
{
u = mod(u*(W-1),W);
v = mod(v*(H-1),H);
int x_small1 = (int)floor(u),
x_small2 = x_small1 - 1,
x_big1 = x_small1 + 1,
x_big2 = x_small1 + 2;
int y_small1 = (int)floor(v),
y_small2 = y_small1 - 1,
y_big1 = y_small1 + 1,
y_big2 = y_small1 + 2;
x_small1 = (int)mod(x_small1,W);
x_small2 = (int)mod(x_small2,W);
x_big1 = (int)mod(x_big1,W);
x_big2 = (int)mod(x_big2,W);
y_small1 = (int)mod(y_small1,H);
y_small2 = (int)mod(y_small2,H);
y_big1 = (int)mod(y_big1,H);
y_big2 = (int)mod(y_big2,H);
double fractional_X = u - x_small1;
double fractional_Y = v - y_small1;
if (nchan == 3)
{
// the interpolations across the rows
Vec3d row1 = cubic(Vec3d(pixel(x_small2, y_small2)[0], pixel(x_small2, y_small2)[1], pixel(x_small2, y_small2)[2]),
Vec3d(pixel(x_small1, y_small2)[0], pixel(x_small1, y_small2)[1], pixel(x_small1, y_small2)[2]),
Vec3d(pixel(x_big1, y_small2)[0], pixel(x_big1, y_small2)[1], pixel(x_big1, y_small2)[2]),
Vec3d(pixel(x_big2, y_small2)[0], pixel(x_big2, y_small2)[1], pixel(x_big2, y_small2)[2]),
fractional_X);
Vec3d row2 = cubic(Vec3d(pixel(x_small2, y_small1)[0], pixel(x_small2, y_small1)[1], pixel(x_small2, y_small1)[2]),
Vec3d(pixel(x_small1, y_small1)[0], pixel(x_small1, y_small1)[1], pixel(x_small1, y_small1)[2]),
Vec3d(pixel(x_big1, y_small1)[0], pixel(x_big1, y_small1)[1], pixel(x_big1, y_small1)[2]),
Vec3d(pixel(x_big2, y_small1)[0], pixel(x_big2, y_small1)[1], pixel(x_big2, y_small1)[2]),
fractional_X);
Vec3d row3 = cubic(Vec3d(pixel(x_small2, y_big1)[0], pixel(x_small2, y_big1)[1], pixel(x_small2, y_big1)[2]),
Vec3d(pixel(x_small1, y_big1)[0], pixel(x_small1, y_big1)[1], pixel(x_small1, y_big1)[2]),
Vec3d(pixel(x_big1, y_big1)[0], pixel(x_big1, y_big1)[1], pixel(x_big1, y_big1)[2]),
Vec3d(pixel(x_big2, y_big1)[0], pixel(x_big2, y_big1)[1], pixel(x_big2, y_big1)[2]),
fractional_X);
Vec3d row4 = cubic(Vec3d(pixel(x_small2, y_big2)[0], pixel(x_small2, y_big2)[1], pixel(x_small2, y_big2)[2]),
Vec3d(pixel(x_small1, y_big2)[0], pixel(x_small1, y_big2)[1], pixel(x_small1, y_big2)[2]),
Vec3d(pixel(x_big1, y_big2)[0], pixel(x_big1, y_big2)[1], pixel(x_big1, y_big2)[2]),
Vec3d(pixel(x_big2, y_big2)[0], pixel(x_big2, y_big2)[1], pixel(x_big2, y_big2)[2]),
fractional_X);
// now interpolate across the interpolated rows (the columns)
return cubic(row1,row2,row3,row4,fractional_Y);
}
else
return Vec3d(0.0);
}
Vec3d bicubic2(double u, double v) const
{
u = mod(u*(W-1),W);
v = mod(v*(H-1),H);
int x_small1 = floorf(u),
x_small2 = x_small1 - 1,
x_big1 = int(x_small1 + 1),
x_big2 = int(x_small1 + 2);
int y_small1 = floorf(v),
y_small2 = y_small1 - 1,
y_big1 = y_small1 + 1,
y_big2 = y_small1 + 2;
x_small1 = (int)mod(x_small1,W);
x_small2 = (int)mod(x_small2,W);
x_big1 = (int)mod(x_big1,W);
x_big2 = (int)mod(x_big2,W);
y_small1 = (int)mod(y_small1,H);
y_small2 = (int)mod(y_small2,H);
y_big1 = (int)mod(y_big1,H);
y_big2 = (int)mod(y_big2,H);
double fractional_X = u - x_small1;
double fractional_Y = v - y_small1;
if (nchan == 3)
{
// the interpolations across the rows
Vec3d row1 = cubic2(Vec3d(pixel(x_small2, y_small2)[0], pixel(x_small2, y_small2)[1], pixel(x_small2, y_small2)[2]),
Vec3d(pixel(x_small1, y_small2)[0], pixel(x_small1, y_small2)[1], pixel(x_small1, y_small2)[2]),
Vec3d(pixel(x_big1, y_small2)[0], pixel(x_big1, y_small2)[1], pixel(x_big1, y_small2)[2]),
Vec3d(pixel(x_big2, y_small2)[0], pixel(x_big2, y_small2)[1], pixel(x_big2, y_small2)[2]),
fractional_X);
Vec3d row2 = cubic2(Vec3d(pixel(x_small2, y_small1)[0], pixel(x_small2, y_small1)[1], pixel(x_small2, y_small1)[2]),
Vec3d(pixel(x_small1, y_small1)[0], pixel(x_small1, y_small1)[1], pixel(x_small1, y_small1)[2]),
Vec3d(pixel(x_big1, y_small1)[0], pixel(x_big1, y_small1)[1], pixel(x_big1, y_small1)[2]),
Vec3d(pixel(x_big2, y_small1)[0], pixel(x_big2, y_small1)[1], pixel(x_big2, y_small1)[2]),
fractional_X);
Vec3d row3 = cubic2(Vec3d(pixel(x_small2, y_big1)[0], pixel(x_small2, y_big1)[1], pixel(x_small2, y_big1)[2]),
Vec3d(pixel(x_small1, y_big1)[0], pixel(x_small1, y_big1)[1], pixel(x_small1, y_big1)[2]),
Vec3d(pixel(x_big1, y_big1)[0], pixel(x_big1, y_big1)[1], pixel(x_big1, y_big1)[2]),
Vec3d(pixel(x_big2, y_big1)[0], pixel(x_big2, y_big1)[1], pixel(x_big2, y_big1)[2]),
fractional_X);
Vec3d row4 = cubic2(Vec3d(pixel(x_small2, y_big2)[0], pixel(x_small2, y_big2)[1], pixel(x_small2, y_big2)[2]),
Vec3d(pixel(x_small1, y_big2)[0], pixel(x_small1, y_big2)[1], pixel(x_small1, y_big2)[2]),
Vec3d(pixel(x_big1, y_big2)[0], pixel(x_big1, y_big2)[1], pixel(x_big1, y_big2)[2]),
Vec3d(pixel(x_big2, y_big2)[0], pixel(x_big2, y_big2)[1], pixel(x_big2, y_big2)[2]),
fractional_X);
// now interpolate across the interpolated rows (the columns)
return cubic2(row1,row2,row3,row4,fractional_Y);
}
else
return Vec3d(0.0);
}
#endif