private ImagePlane[] Convolution(ImagePlane[] inputPlanes, double[] W, int nOutputPlane, double[] bias)
{
int width = inputPlanes[0].Width;
int height = inputPlanes[0].Height;
ImagePlane[] outputPlanes = new ImagePlane[nOutputPlane];
for (int o = 0; o < nOutputPlane; o++)
{
outputPlanes[o] = new ImagePlane(width - 2, height - 2);
}
double[] sumValues = new double[nOutputPlane];
double[] biasValues = new double[nOutputPlane];
bias.CopyTo(biasValues, 0);
for (int w = 1; w < width - 1; w++)
{
for (int h = 1; h < height - 1; h++)
{
biasValues.CopyTo(sumValues, 0); // leaky ReLU bias
for (int i = 0; i < inputPlanes.Length; i++)
{
double i00 = inputPlanes[i].GetValue(w - 1, h - 1);
double i10 = inputPlanes[i].GetValue(w, h - 1);
double i20 = inputPlanes[i].GetValue(w + 1, h - 1);
double i01 = inputPlanes[i].GetValue(w - 1, h);
double i11 = inputPlanes[i].GetValue(w, h);
double i21 = inputPlanes[i].GetValue(w + 1, h);
double i02 = inputPlanes[i].GetValue(w - 1, h + 1);
double i12 = inputPlanes[i].GetValue(w, h + 1);
double i22 = inputPlanes[i].GetValue(w + 1, h + 1);
for (int o = 0; o < nOutputPlane; o++)
{
int weightIndex = (o * inputPlanes.Length * 9) + (i * 9);
double value = sumValues[o];
value += i00 * W[weightIndex++];
value += i10 * W[weightIndex++];
value += i20 * W[weightIndex++];
value += i01 * W[weightIndex++];
value += i11 * W[weightIndex++];
value += i21 * W[weightIndex++];
value += i02 * W[weightIndex++];
value += i12 * W[weightIndex++];
value += i22 * W[weightIndex++];
sumValues[o] = value;
}
}
for (int o = 0; o < nOutputPlane; o++)
{
double v = sumValues[o];
if (v < 0)
{
v *= 0.1;
}
outputPlanes[o].SetValue(w - 1, h - 1, v);
}
}
}
return(outputPlanes);
}
private ImageChannel Denormalize(ImagePlane imagePlane)
{
ImageChannel image = new ImageChannel(imagePlane.Width, imagePlane.Height);
for (int i = 0; i < imagePlane.Buffer.Length; i++)
{
double temp = Math.Round(imagePlane.Buffer[i] * 255, MidpointRounding.AwayFromZero);
image.Buffer[i] = temp > 255? (byte)255: (byte)temp;
}
return(image);
}
public static ImagePlane[] Deblocking(ImagePlane[][] outputBlocks, int blocksWidth, int blocksHeight)
{
int blockSize = outputBlocks[0][0].Width;
int width = 0;
for (int b = 0; b < blocksWidth; b++)
{
width += outputBlocks[b][0].Width;
}
int height = 0;
for (int b = 0; b < blocksWidth * blocksHeight; b += blocksWidth)
{
height += outputBlocks[b][0].Height;
}
//console.log("result image width:" + width + " height:" + height);
List <ImagePlane> outputPlanes = new List <ImagePlane>(); // [ planeR, planeG, planeB ]
for (int b = 0; b < outputBlocks.Length; b++)
{
ImagePlane[] block = outputBlocks[b];
int blockWidthIndex = b % blocksWidth;
int blockHeightIndex = (int)Math.Floor((double)b / blocksWidth);
for (int n = 0; n < block.Length; n++)
{
if (outputPlanes.Count < n + 1)
{
outputPlanes.Add(new ImagePlane(width, height));
}
else if (outputPlanes[n] == null)
{
outputPlanes[n] = new ImagePlane(width, height);
}
ImagePlane channelBlock = block[n];
for (int w = 0; w < channelBlock.Width; w++)
{
for (int h = 0; h < channelBlock.Height; h++)
{
int targetIndexW = blockWidthIndex * blockSize + w;
int targetIndexH = blockHeightIndex * blockSize + h;
int targetIndex = targetIndexH * width + targetIndexW;
double channelValue = channelBlock.GetValue(w, h);
outputPlanes[n].Buffer[targetIndex] = channelValue;
}
}
}
}
return(outputPlanes.ToArray());
}
private ImagePlane Normalize(ImageChannel image)
{
int width = image.Width;
int height = image.Height;
ImagePlane imagePlane = new ImagePlane(width, height);
if (imagePlane.Buffer.Length != image.Buffer.Length)
{
throw new Exception("Assertion error: length");
}
for (int i = 0; i < image.Buffer.Length; i++)
{
double temp = image.Buffer[i] / 255.0;
imagePlane.Buffer[i] = temp;
}
return(imagePlane);
}
private ImageChannels UpscaleRgbAsync(Guid taskId, ImageChannels channels, SRCNNModelLayer[] model, int scale, Action <ProgressMessage> progressCallback)
{
ImagePlane[] inputPlanes = channels.ToArray().Select((image) =>
{
ImageChannel imgResized = scale == 1 ? image : image.Resize(scale);
// extrapolation for layer count (each convolution removes outer 1 pixel border)
ImageChannel imgExtra = imgResized.Extrapolation(model.Length);
return(Normalize(imgExtra));
}).ToArray();
// blocking
ImageBlocks imageBlocks = ImagePlane.Blocking(inputPlanes);
inputPlanes = null;
// init W
double[][] weights = GetWeights(model);
var outputBlocks = imageBlocks.Blocks.AsParallel()
.SelectMany((block, index) => UpscaleBlocks(taskId, model, weights, progressCallback,
index + 1, imageBlocks.Blocks.Count,
block))
.ToList();
// de-blocking
ImagePlane[] outputPlanes = ImagePlane.Deblocking(outputBlocks.ToArray(), imageBlocks.BlocksWidth, imageBlocks.BlocksHeight);
if (outputPlanes.Length != 3)
{
throw new Exception("Output planes must be 3: color channel R, G, B.");
}
ImageChannels outputChannels = new ImageChannels()
{
Red = Denormalize(outputPlanes[0]),
Green = Denormalize(outputPlanes[1]),
Blue = Denormalize(outputPlanes[2]),
Alpha = channels.Alpha
};
return(outputChannels);
}
public static ImageBlocks Blocking(ImagePlane[] initialPlanes)
{
int widthInput = initialPlanes[0].Width;
int heightInput = initialPlanes[0].Height;
int blocksWidth = (int)Math.Ceiling((double)(widthInput - Overlap) / (BlockSize - Overlap));
int blocksHeight = (int)Math.Ceiling((double)(heightInput - Overlap) / (BlockSize - Overlap));
int blocks = blocksWidth * blocksHeight;
ImageBlocks inputBlocks = new ImageBlocks() // [ [ block0_R, block0_G, block0_B ], [ block1_R, ...] ... ]
{
BlocksWidth = blocksWidth,
BlocksHeight = blocksHeight
};
for (int b = 0; b < blocks; b++)
{
int blockWidthIndex = b % blocksWidth;
int blockHeightIndex = (int)Math.Floor((double)(b / blocksWidth));
int blockWidth;
int blockHeight;
if (blockWidthIndex == blocksWidth - 1)
{
blockWidth = widthInput - ((BlockSize - Overlap) * blockWidthIndex); // right end block
}
else
{
blockWidth = BlockSize;
}
if (blockHeightIndex == blocksHeight - 1)
{
blockHeight = heightInput - ((BlockSize - Overlap) * blockHeightIndex); // bottom end block
}
else
{
blockHeight = BlockSize;
}
ImagePlane[] channels = new ImagePlane[initialPlanes.Length];
for (int i = 0; i < channels.Length; i++)
{
channels[i] = new ImagePlane(blockWidth, blockHeight);
}
for (int w = 0; w < blockWidth; w++)
{
for (int h = 0; h < blockHeight; h++)
{
for (int n = 0; n < initialPlanes.Length; n++)
{
int targetIndexW = blockWidthIndex * (BlockSize - Overlap) + w;
int targetIndexH = blockHeightIndex * (BlockSize - Overlap) + h;
ImagePlane channel = initialPlanes[n];
double channelValue = channel.GetValue(targetIndexW, targetIndexH);
channels[n].SetValue(w, h, channelValue);
}
}
}
inputBlocks.Blocks.Add(channels);
}
return(inputBlocks);
}