/// <summary>
/// Convolve with a kernel consisting of one column.
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="alpha"></param>
/// <param name="edgeAction"></param>
public static void ConvolveV(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, bool alpha, EdgeMode edgeAction) {
int index = 0;
float[] matrix = kernel.GetKernel();
int rows = kernel.Height;
int rows2 = rows/2;
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
for (int row = -rows2; row <= rows2; row++) {
int iy = y + row;
int ioffset;
if (iy < 0) {
if (edgeAction == EdgeMode.Clamp)
ioffset = 0;
else if (edgeAction == EdgeMode.Wrap)
ioffset = ((y + height)%height)*width;
else
ioffset = iy*width;
}
else if (iy >= height) {
if (edgeAction == EdgeMode.Clamp)
ioffset = (height - 1)*width;
else if (edgeAction == EdgeMode.Wrap)
ioffset = ((y + height)%height)*width;
else
ioffset = iy*width;
}
else
ioffset = iy*width;
float f = matrix[row + rows2];
if (f != 0) {
int rgb = inPixels[ioffset + x];
a += f*((rgb >> 24) & 0xff);
r += f*((rgb >> 16) & 0xff);
g += f*((rgb >> 8) & 0xff);
b += f*(rgb & 0xff);
}
}
int ia = alpha ? PixelUtils.Clamp((int)(a + 0.5)) : 0xff;
int ir = PixelUtils.Clamp((int)(r + 0.5));
int ig = PixelUtils.Clamp((int)(g + 0.5));
int ib = PixelUtils.Clamp((int)(b + 0.5));
outPixels[index++] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
}
}
}
/// <summary>
/// Construct a filter with the given 3x3 kernel.
/// </summary>
/// <param name="kernel"></param>
public ConvolveFilter(Kernel kernel) {
UseAlpha = true;
PremultiplyAlpha = true;
Kernel = kernel;
}
/// <summary>
/// Convolve with a kernel consisting of one row.
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="alpha"></param>
/// <param name="edgeAction"></param>
public static void ConvolveH(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, bool alpha, EdgeMode edgeAction) {
int index = 0;
float[] matrix = kernel.GetKernel();
int cols = kernel.Width;
int cols2 = cols/2;
for (int y = 0; y < height; y++) {
int ioffset = y*width;
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
int moffset = cols2;
for (int col = -cols2; col <= cols2; col++) {
float f = matrix[moffset + col];
if (f != 0) {
int ix = x + col;
if (ix < 0) {
if (edgeAction == EdgeMode.Clamp)
ix = 0;
else if (edgeAction == EdgeMode.Wrap)
ix = (x + width)%width;
}
else if (ix >= width) {
if (edgeAction == EdgeMode.Clamp)
ix = width - 1;
else if (edgeAction == EdgeMode.Wrap)
ix = (x + width)%width;
}
int rgb = inPixels[ioffset + ix];
a += f*((rgb >> 24) & 0xff);
r += f*((rgb >> 16) & 0xff);
g += f*((rgb >> 8) & 0xff);
b += f*(rgb & 0xff);
}
}
int ia = alpha ? PixelUtils.Clamp((int)(a + 0.5)) : 0xff;
int ir = PixelUtils.Clamp((int)(r + 0.5));
int ig = PixelUtils.Clamp((int)(g + 0.5));
int ib = PixelUtils.Clamp((int)(b + 0.5));
outPixels[index++] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
}
}
}
/// <summary>
/// Convolve with a 2D kernel.
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="alpha"></param>
/// <param name="edgeAction"></param>
public static void ConvolveHV(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, bool alpha, EdgeMode edgeAction) {
int index = 0;
float[] matrix = kernel.GetKernel();
int rows = kernel.Height;
int cols = kernel.Width;
int rows2 = rows/2;
int cols2 = cols/2;
for (int y = 0; y < height; y++) {
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
for (int row = -rows2; row <= rows2; row++) {
int iy = y + row;
int ioffset;
if (0 <= iy && iy < height)
ioffset = iy*width;
else if (edgeAction == EdgeMode.Clamp)
ioffset = y*width;
else if (edgeAction == EdgeMode.Wrap)
ioffset = ((iy + height)%height)*width;
else
continue;
int moffset = cols*(row + rows2) + cols2;
for (int col = -cols2; col <= cols2; col++) {
float f = matrix[moffset + col];
if (f != 0) {
int ix = x + col;
if (!(0 <= ix && ix < width)) {
if (edgeAction == EdgeMode.Clamp)
ix = x;
else if (edgeAction == EdgeMode.Wrap)
ix = (x + width)%width;
else
continue;
}
int rgb = inPixels[ioffset + ix];
a += f*((rgb >> 24) & 0xff);
r += f*((rgb >> 16) & 0xff);
g += f*((rgb >> 8) & 0xff);
b += f*(rgb & 0xff);
}
}
}
int ia = alpha ? PixelUtils.Clamp((int)(a + 0.5)) : 0xff;
int ir = PixelUtils.Clamp((int)(r + 0.5));
int ig = PixelUtils.Clamp((int)(g + 0.5));
int ib = PixelUtils.Clamp((int)(b + 0.5));
outPixels[index++] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
}
}
}
/// <summary>
/// Convolve a block of pixels
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="alpha"></param>
/// <param name="edgeAction"></param>
public static void Convolve(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, bool alpha, EdgeMode edgeAction) {
if (kernel.Height == 1)
ConvolveH(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
else if (kernel.Width == 1)
ConvolveV(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
else
ConvolveHV(kernel, inPixels, outPixels, width, height, alpha, edgeAction);
}
/// <summary>
/// Convolve a block of pixels.
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="edgeAction"></param>
public static void Convolve(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, EdgeMode edgeAction) {
Convolve(kernel, inPixels, outPixels, width, height, true, edgeAction);
}
/// <summary>
/// Blur and transpose a block of ARGB pixels.
/// </summary>
/// <param name="kernel"></param>
/// <param name="inPixels"></param>
/// <param name="outPixels"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="alpha"></param>
/// <param name="premultiply"></param>
/// <param name="unpremultiply"></param>
/// <param name="edgeAction"></param>
public static void ConvolveAndTranspose(Kernel kernel, int[] inPixels, int[] outPixels, int width, int height, bool alpha, bool premultiply, bool unpremultiply, EdgeMode edgeAction) {
float[] matrix = kernel.GetKernel();
int cols = kernel.Width;
int cols2 = cols/2;
for (int y = 0; y < height; y++) {
int index = y;
int ioffset = y*width;
for (int x = 0; x < width; x++) {
float r = 0, g = 0, b = 0, a = 0;
int moffset = cols2;
for (int col = -cols2; col <= cols2; col++) {
float f = matrix[moffset + col];
if (f != 0) {
int ix = x + col;
if (ix < 0) {
if (edgeAction == EdgeMode.Clamp)
ix = 0;
else if (edgeAction == EdgeMode.Wrap)
ix = (x + width)%width;
}
else if (ix >= width) {
if (edgeAction == EdgeMode.Clamp)
ix = width - 1;
else if (edgeAction == EdgeMode.Wrap)
ix = (x + width)%width;
}
int rgb = inPixels[ioffset + ix];
int pa = (rgb >> 24) & 0xff;
int pr = (rgb >> 16) & 0xff;
int pg = (rgb >> 8) & 0xff;
int pb = rgb & 0xff;
if (premultiply) {
float a255 = pa*(1.0f/255.0f);
pr = (int)(pr*a255);
pg = (int)(pg*a255);
pb = (int)(pb*a255);
}
a += f*pa;
r += f*pr;
g += f*pg;
b += f*pb;
}
}
if (unpremultiply && a != 0 && a != 255) {
float f = 255.0f/a;
r *= f;
g *= f;
b *= f;
}
int ia = alpha ? PixelUtils.Clamp((int)(a + 0.5)) : 0xff;
int ir = PixelUtils.Clamp((int)(r + 0.5));
int ig = PixelUtils.Clamp((int)(g + 0.5));
int ib = PixelUtils.Clamp((int)(b + 0.5));
outPixels[index] = (ia << 24) | (ir << 16) | (ig << 8) | ib;
index += height;
}
}
}
