/*
* input kernel area naming convention:
* -------------
| A | B | C |
| ----|---|---|
| D | E | F | //input pixel is at position E
| ----|---|---|
| G | H | I |
| -------------
| blendInfo: result of preprocessing all four corners of pixel "e"
*/
private void ScalePixel(IScaler scaler, int rotDeg, Kernel3x3 ker, int trgi, char blendInfo)
{
// int a = ker._[Rot._[(0 << 2) + rotDeg]];
var b = ker._[Rot._[(1 << 2) + rotDeg]];
var c = ker._[Rot._[(2 << 2) + rotDeg]];
var d = ker._[Rot._[(3 << 2) + rotDeg]];
var e = ker._[Rot._[(4 << 2) + rotDeg]];
var f = ker._[Rot._[(5 << 2) + rotDeg]];
var g = ker._[Rot._[(6 << 2) + rotDeg]];
var h = ker._[Rot._[(7 << 2) + rotDeg]];
var i = ker._[Rot._[(8 << 2) + rotDeg]];
var blend = blendInfo.Rotate((RotationDegree)rotDeg);
if ((BlendType)blend.GetBottomR() == BlendType.None)
{
return;
}
var eq = _colorEqualizer;
var dist = _colorDistance;
bool doLineBlend;
if (blend.GetBottomR() >= (char)BlendType.Dominant)
{
doLineBlend = true;
}
//make sure there is no second blending in an adjacent
//rotation for this pixel: handles insular pixels, mario eyes
//but support double-blending for 90� corners
else if (blend.GetTopR() != (char)BlendType.None && !eq.IsColorEqual(e, g))
{
doLineBlend = false;
}
else if (blend.GetBottomL() != (char)BlendType.None && !eq.IsColorEqual(e, c))
{
doLineBlend = false;
}
//no full blending for L-shapes; blend corner only (handles "mario mushroom eyes")
else if (eq.IsColorEqual(g, h) && eq.IsColorEqual(h, i) && eq.IsColorEqual(i, f) && eq.IsColorEqual(f, c) && !eq.IsColorEqual(e, i))
{
doLineBlend = false;
}
else
{
doLineBlend = true;
}
//choose most similar color
var px = dist.DistYCbCr(e, f) <= dist.DistYCbCr(e, h) ? f : h;
var out_ = _outputMatrix;
out_.Move(rotDeg, trgi);
if (!doLineBlend)
{
scaler.BlendCorner(px, out_);
return;
}
//test sample: 70% of values max(fg, hc) / min(fg, hc)
//are between 1.1 and 3.7 with median being 1.9
var fg = dist.DistYCbCr(f, g);
var hc = dist.DistYCbCr(h, c);
var haveShallowLine = _cfg.SteepDirectionThreshold * fg <= hc && e != g && d != g;
var haveSteepLine = _cfg.SteepDirectionThreshold * hc <= fg && e != c && b != c;
if (haveShallowLine)
{
if (haveSteepLine)
{
scaler.BlendLineSteepAndShallow(px, out_);
}
else
{
scaler.BlendLineShallow(px, out_);
}
}
else
{
if (haveSteepLine)
{
scaler.BlendLineSteep(px, out_);
}
else
{
scaler.BlendLineDiagonal(px, out_);
}
}
}
//scaler policy: see "Scaler2x" reference implementation
private void ScaleImageImpl(int[] src, int[] trg, int srcWidth, int srcHeight, int yFirst, int yLast)
{
yFirst = Math.Max(yFirst, 0);
yLast = Math.Min(yLast, srcHeight);
if (yFirst >= yLast || srcWidth <= 0)
{
return;
}
var trgWidth = srcWidth * _scaler.Scale;
//temporary buffer for "on the fly preprocessing"
var preProcBuffer = new char[srcWidth];
var ker4 = new Kernel4x4();
//initialize preprocessing buffer for first row:
//detect upper left and right corner blending
//this cannot be optimized for adjacent processing
//stripes; we must not allow for a memory race condition!
if (yFirst > 0)
{
var y = yFirst - 1;
var sM1 = srcWidth * Math.Max(y - 1, 0);
var s0 = srcWidth * y; //center line
var sP1 = srcWidth * Math.Min(y + 1, srcHeight - 1);
var sP2 = srcWidth * Math.Min(y + 2, srcHeight - 1);
for (var x = 0; x < srcWidth; ++x)
{
var xM1 = Math.Max(x - 1, 0);
var xP1 = Math.Min(x + 1, srcWidth - 1);
var xP2 = Math.Min(x + 2, srcWidth - 1);
//read sequentially from memory as far as possible
ker4.A = src[sM1 + xM1];
ker4.B = src[sM1 + x];
ker4.C = src[sM1 + xP1];
ker4.D = src[sM1 + xP2];
ker4.E = src[s0 + xM1];
ker4.F = src[s0 + x];
ker4.G = src[s0 + xP1];
ker4.H = src[s0 + xP2];
ker4.I = src[sP1 + xM1];
ker4.J = src[sP1 + x];
ker4.K = src[sP1 + xP1];
ker4.L = src[sP1 + xP2];
ker4.M = src[sP2 + xM1];
ker4.N = src[sP2 + x];
ker4.O = src[sP2 + xP1];
ker4.P = src[sP2 + xP2];
PreProcessCorners(ker4); // writes to blendResult
/*
* preprocessing blend result:
* ---------
| F | G | //evalute corner between F, G, J, K
| ----|---| //input pixel is at position F
| J | K |
| ---------
*/
preProcBuffer[x] = preProcBuffer[x].SetTopR(_blendResult.J);
if (x + 1 < srcWidth)
{
preProcBuffer[x + 1] = preProcBuffer[x + 1].SetTopL(_blendResult.K);
}
}
}
_outputMatrix = new OutputMatrix(_scaler.Scale, trg, trgWidth);
var ker3 = new Kernel3x3();
for (var y = yFirst; y < yLast; ++y)
{
//consider MT "striped" access
var trgi = _scaler.Scale * y * trgWidth;
var sM1 = srcWidth * Math.Max(y - 1, 0);
var s0 = srcWidth * y; //center line
var sP1 = srcWidth * Math.Min(y + 1, srcHeight - 1);
var sP2 = srcWidth * Math.Min(y + 2, srcHeight - 1);
var blendXy1 = (char)0;
for (var x = 0; x < srcWidth; ++x, trgi += _scaler.Scale)
{
var xM1 = Math.Max(x - 1, 0);
var xP1 = Math.Min(x + 1, srcWidth - 1);
var xP2 = Math.Min(x + 2, srcWidth - 1);
//evaluate the four corners on bottom-right of current pixel
//blend_xy for current (x, y) position
//read sequentially from memory as far as possible
ker4.A = src[sM1 + xM1];
ker4.B = src[sM1 + x];
ker4.C = src[sM1 + xP1];
ker4.D = src[sM1 + xP2];
ker4.E = src[s0 + xM1];
ker4.F = src[s0 + x];
ker4.G = src[s0 + xP1];
ker4.H = src[s0 + xP2];
ker4.I = src[sP1 + xM1];
ker4.J = src[sP1 + x];
ker4.K = src[sP1 + xP1];
ker4.L = src[sP1 + xP2];
ker4.M = src[sP2 + xM1];
ker4.N = src[sP2 + x];
ker4.O = src[sP2 + xP1];
ker4.P = src[sP2 + xP2];
PreProcessCorners(ker4); // writes to blendResult
/*
* preprocessing blend result:
* ---------
| F | G | //evaluate corner between F, G, J, K
| ----|---| //current input pixel is at position F
| J | K |
| ---------
*/
//all four corners of (x, y) have been determined at
//this point due to processing sequence!
var blendXy = preProcBuffer[x].SetBottomR(_blendResult.F);
//set 2nd known corner for (x, y + 1)
blendXy1 = blendXy1.SetTopR(_blendResult.J);
//store on current buffer position for use on next row
preProcBuffer[x] = blendXy1;
//set 1st known corner for (x + 1, y + 1) and
//buffer for use on next column
blendXy1 = ((char)0).SetTopL(_blendResult.K);
if (x + 1 < srcWidth)
{
//set 3rd known corner for (x + 1, y)
preProcBuffer[x + 1] = preProcBuffer[x + 1].SetBottomL(_blendResult.G);
}
//fill block of size scale * scale with the given color
// //place *after* preprocessing step, to not overwrite the
// //results while processing the the last pixel!
FillBlock(trg, trgi, trgWidth, src[s0 + x], _scaler.Scale);
//blend four corners of current pixel
if (blendXy == 0)
{
continue;
}
const int a = 0, b = 1, c = 2, d = 3, e = 4, f = 5, g = 6, h = 7, i = 8;
//read sequentially from memory as far as possible
ker3._[a] = src[sM1 + xM1];
ker3._[b] = src[sM1 + x];
ker3._[c] = src[sM1 + xP1];
ker3._[d] = src[s0 + xM1];
ker3._[e] = src[s0 + x];
ker3._[f] = src[s0 + xP1];
ker3._[g] = src[sP1 + xM1];
ker3._[h] = src[sP1 + x];
ker3._[i] = src[sP1 + xP1];
ScalePixel(_scaler, (int)RotationDegree.R0, ker3, trgi, blendXy);
ScalePixel(_scaler, (int)RotationDegree.R90, ker3, trgi, blendXy);
ScalePixel(_scaler, (int)RotationDegree.R180, ker3, trgi, blendXy);
ScalePixel(_scaler, (int)RotationDegree.R270, ker3, trgi, blendXy);
}
}
}
public void AddImage(SpanBitmap image)
{
Kernel3x3 <Pixel.BGR96F> .Process(image, _Laplacian_EdgeDetector, pixel => this.AddSample(_MaxOf(pixel)));
}