// Very simple and inadequate greyscale conversion, but it'll do
static public ByteImage ToGreyscale(ByteImage inputImage, bool alpha100 = true)
{
byte[] inputImageData = inputImage.imageData;
int width = inputImage.width;
int height = inputImage.height;
int stride = inputImage.stride;
byte[] output = new byte[inputImageData.Length];
int strideHere = 0;
int xX4;
int offsetHere;
byte tmpLuma;
for (int y = 0; y < height; y++)
{
strideHere = stride * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHere = strideHere + xX4;
tmpLuma = (byte)(inputImageData[offsetHere] * 0.11 + 0.59 * inputImageData[offsetHere + 1] + 0.3 * inputImageData[offsetHere + 2]);
output[offsetHere] = tmpLuma;
output[offsetHere + 1] = tmpLuma;
output[offsetHere + 2] = tmpLuma;
output[offsetHere + 3] = alpha100 ? (byte)255 : inputImageData[offsetHere + 3];
}
}
return(new ByteImage(output, stride, width, height, inputImage.pixelFormat));
}
static public FloatImage FromByteImage(ByteImage inputImage)
{
byte[] inputImageData = inputImage.imageData;
int width = inputImage.width, height = inputImage.height, stride = inputImage.stride;
PixelFormat pixelFormat = inputImage.pixelFormat;
float[] output = new float[inputImageData.Length];
int strideHere = 0;
int xX4;
int offsetHere;
for (int y = 0; y < height; y++)
{
strideHere = stride * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHere = strideHere + xX4;
output[offsetHere] = (float)inputImageData[offsetHere];
output[offsetHere + 1] = (float)inputImageData[offsetHere + 1];
output[offsetHere + 2] = (float)inputImageData[offsetHere + 2];
output[offsetHere + 3] = (float)inputImageData[offsetHere + 3];
}
}
return(new FloatImage(output, stride, width, height, pixelFormat));
}
public static Bitmap ByteArrayToBitmap(ByteImage byteImage)
{
Bitmap myBitmap = new Bitmap(byteImage.width, byteImage.height, byteImage.pixelFormat);
Rectangle rect = new Rectangle(0, 0, myBitmap.Width, myBitmap.Height);
System.Drawing.Imaging.BitmapData bmpData =
myBitmap.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadWrite,
myBitmap.PixelFormat);
bmpData.Stride = byteImage.stride;
IntPtr ptr = bmpData.Scan0;
System.Runtime.InteropServices.Marshal.Copy(byteImage.imageData, 0, ptr, byteImage.imageData.Length);
myBitmap.UnlockBits(bmpData);
return(myBitmap);
}
// Simple 1D Greyscale regrade of one image to another. Basically just to match brightness, that's all.
static public FloatImage Regrade1DSimpleLUT(ByteImage testImage, ByteImage referenceImage)
{
byte[] testImageData = testImage.imageData;
byte[] referenceImageData = referenceImage.imageData;
float[] output = new float[testImage.Length];
// Build histogram
AverageData1D[] FactorLUT = new AverageData1D[256];
int width = testImage.width;
int height = testImage.height;
int strideTest = testImage.stride;
int strideRef = referenceImage.stride;
int strideHereTest, strideHereRef = 0;
int xX4;
int offsetHereTest, offsetHereRef;
float testLuma, refLuma;
float hereFactor;
for (int y = 0; y < height; y++)
{
strideHereTest = strideTest * y;
strideHereRef = strideRef * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHereTest = strideHereTest + xX4;
offsetHereRef = strideHereRef + xX4;
testLuma = testImageData[offsetHereTest] * 0.11f + 0.59f * testImageData[offsetHereTest + 1] + 0.3f * testImageData[offsetHereTest + 2];
refLuma = referenceImageData[offsetHereRef] * 0.11f + 0.59f * referenceImageData[offsetHereRef + 1] + 0.3f * referenceImageData[offsetHereRef + 2];
FactorLUT[(int)testLuma].color += refLuma / testLuma;
FactorLUT[(int)testLuma].divisor++;
/*output[offsetHereTest] = tmpLuma;
* output[offsetHereTest + 1] = tmpLuma;
* output[offsetHereTest + 2] = tmpLuma;
* output[offsetHereTest + 3] = testImageData[offsetHere + 3];*/
}
}
// Evaluate histogram
// No interpolation bc it only has to apply to this one image.
for (int i = 0; i < 256; i++)
{
if (FactorLUT[i].divisor != 0)
{
FactorLUT[i].color = FactorLUT[i].color / FactorLUT[i].divisor;
}
}
// Apply histogram
for (int y = 0; y < height; y++)
{
strideHereTest = strideTest * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHereTest = strideHereTest + xX4;
testLuma = testImageData[offsetHereTest] * 0.11f + 0.59f * testImageData[offsetHereTest + 1] + 0.3f * testImageData[offsetHereTest + 2];
hereFactor = FactorLUT[(int)testLuma].color;
output[offsetHereTest] = testImageData[offsetHereTest] * hereFactor;
output[offsetHereTest + 1] = testImageData[offsetHereTest + 1] * hereFactor;
output[offsetHereTest + 2] = testImageData[offsetHereTest + 2] * hereFactor;
output[offsetHereTest + 3] = testImageData[offsetHereTest + 3];
}
}
return(new FloatImage(output, strideTest, width, height, testImage.pixelFormat));
}
// Simple 1D Greyscale regrade of one image to another. Basically just to match brightness, that's all.
static public FloatImage Regrade1DHistogram(ByteImage testImage, ByteImage referenceImage, int percentileSubdivisions = 100, int smoothradius = 20, float smoothIntensity = 1f)
{
byte[] testImageData = testImage.imageData;
byte[] referenceImageData = referenceImage.imageData;
float[] output = new float[testImage.Length];
// Work in 16 bit for more precision in the percentile thing.
int sixteenBitCount = 256 * 256;
int sixteenBitMax = sixteenBitCount - 1;
// Build histogram
int[] histogramTest = new int[sixteenBitCount];
int[] histogramRef = new int[sixteenBitCount];
int width = testImage.width;
int height = testImage.height;
int strideTest = testImage.stride;
int strideRef = referenceImage.stride;
int strideHereTest, strideHereRef = 0;
int xX4;
int offsetHereTest, offsetHereRef;
int testLuma, refLuma;
float hereFactor;
// 1. BUILD HISTOGRAMS
for (int y = 0; y < height; y++)
{
strideHereTest = strideTest * y;
strideHereRef = strideRef * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHereTest = strideHereTest + xX4;
offsetHereRef = strideHereRef + xX4;
// Add 1 to avoid division by zero issues, subtract later again.
testLuma = 1 + (int)Math.Max(0, Math.Min(sixteenBitMax, (((int)testImageData[offsetHereTest] << 8) * 0.11f + 0.59f * ((int)testImageData[offsetHereTest + 1] << 8) + 0.3f * ((int)testImageData[offsetHereTest + 2] << 8))));
refLuma = 1 + (int)Math.Max(0, Math.Min(sixteenBitMax, (((int)referenceImageData[offsetHereRef] << 8) * 0.11f + 0.59f * ((int)referenceImageData[offsetHereRef + 1] << 8) + 0.3f * ((int)referenceImageData[offsetHereRef + 2] << 8))));
histogramTest[testLuma]++;
histogramRef[refLuma]++;
/*output[offsetHereTest] = tmpLuma;
* output[offsetHereTest + 1] = tmpLuma;
* output[offsetHereTest + 2] = tmpLuma;
* output[offsetHereTest + 3] = testImageData[offsetHere + 3];*/
}
}
// Info: The subdivision count is the amount of "boxes" I divide the brightness spectrum into. But these arrays do not represent the boxes, but rather the splits between the boxes, so it's -1. The splits define exactly WHERE the boxes end.
FloatIssetable[] percentilesTest = new FloatIssetable[percentileSubdivisions - 1];
FloatIssetable[] percentilesRef = new FloatIssetable[percentileSubdivisions - 1];
float onePercentile = width * height / percentileSubdivisions; // This is a bit messy I guess but it should work out.
// 2. BUILD PERCENTILE ARRAYS
// Fill percentile-arrays, basically saying at which brightness a certain percentile starts, by the amount of pixels that have a certain brightness
int countTest = 0;
int currentPercentileTest = 0, lastPercentileTest = 0;
float lastTestPercentileJumpValue = 0;
int countRef = 0;
int currentPercentileRef = 0, lastPercentileRef = 0;
float lastRefPercentileJumpValue = 0;
for (int i = 0; i < sixteenBitCount; i++)
{
countTest += histogramTest[i];
currentPercentileTest = (int)Math.Min(percentileSubdivisions - 1, Math.Floor((double)countTest / onePercentile));
if (currentPercentileTest != lastPercentileTest)
{
percentilesTest[currentPercentileTest - 1].value = i;
percentilesTest[currentPercentileTest - 1].isSet = true;
// Fill holes, if there are any.
for (int a = lastPercentileTest + 1; a < currentPercentileTest; a++)
{
percentilesTest[a - 1].value = lastTestPercentileJumpValue + (i - lastTestPercentileJumpValue) * ((a - lastPercentileTest) / ((float)currentPercentileTest - lastPercentileTest));
percentilesTest[a - 1].isSet = true;
}
lastTestPercentileJumpValue = i;
}
lastPercentileTest = currentPercentileTest;
countRef += histogramRef[i];
currentPercentileRef = (int)Math.Min(percentileSubdivisions - 1, Math.Floor((double)countRef / onePercentile));
if (currentPercentileRef != lastPercentileRef)
{
percentilesRef[currentPercentileRef - 1].value = i;
percentilesRef[currentPercentileRef - 1].isSet = true;
// Fill holes, if there are any.
for (int a = lastPercentileRef + 1; a < currentPercentileRef; a++)
{
//percentilesRef[a - 1].value = lastRefPercentileJumpValue + (i - lastRefPercentileJumpValue) * (currentPercentileRef - lastPercentileRef) / a;
percentilesRef[a - 1].value = lastRefPercentileJumpValue + (i - lastRefPercentileJumpValue) * ((a - currentPercentileRef) / ((float)currentPercentileRef - lastPercentileRef));
percentilesRef[a - 1].isSet = true;
}
lastRefPercentileJumpValue = i;
}
lastPercentileRef = currentPercentileRef;
}
// 3. BUILD LUT FROM PERCENTILE ARRAYS
FloatIssetable[] factorsLUT = new FloatIssetable[256];
for (int i = 0; i < percentilesTest.Length; i++)
{
factorsLUT[(int)Math.Floor(percentilesTest[i].value / 256)].value = percentilesTest[i].value == 0 ? 0 : percentilesRef[i].value / percentilesTest[i].value;
factorsLUT[(int)Math.Floor(percentilesTest[i].value / 256)].isSet = true;
}
// 4. FILL HOLES IN LUT
bool lastExists = false, nextExists = false;
int lastExisting = 0, nextExisting = 0;
float linearInterpolationFactor = 0;
for (int i = 0; i < 256; i++)
{
if (factorsLUT[i].isSet == false)
{
// Find next set value, if it exisst
nextExists = false;
for (int a = i + 1; a < 256; a++)
{
if (factorsLUT[a].isSet)
{
nextExists = true;
nextExisting = a;
break;
}
}
if (nextExists && lastExists)
{
linearInterpolationFactor = ((float)i - lastExisting) / (nextExisting - lastExisting);
factorsLUT[i].value = factorsLUT[lastExisting].value + linearInterpolationFactor * (factorsLUT[nextExisting].value - factorsLUT[lastExisting].value);
factorsLUT[i].isSet = true;
lastExists = true;
lastExisting = i;
}
else if (lastExists)
{
factorsLUT[i].value = factorsLUT[lastExisting].value;
factorsLUT[i].isSet = true;
lastExists = true;
lastExisting = i;
}
else if (nextExists)
{
factorsLUT[i].value = factorsLUT[nextExisting].value;
factorsLUT[i].isSet = true;
lastExists = true;
lastExisting = i;
}
else if (!nextExists && !lastExists)
{
// Kinda impossible but ok
// I think we're kinda fucced then. Let's just assume this never happens
}
}
else
{
// Do nothing, all good
lastExists = true;
lastExisting = i;
}
}
// 5. SMOOTH LUT
// Simple 1D "Box" blur. So, a line blur?
// TODO find a way to protect blacks
if (smoothIntensity > 0)
{
float[] elevation = new float[factorsLUT.Length - 1];
float[] elevationSmoothed = new float[factorsLUT.Length - 1];
float totalElevation = 0;
float totalElevationSmoothed = 0;
float blackPoint = float.PositiveInfinity;
float whitePoint = 0;
float startPoint = factorsLUT[0].value;
if (factorsLUT[0].value > whitePoint)
{
whitePoint = factorsLUT[0].value;
}
if (factorsLUT[0].value < blackPoint)
{
blackPoint = factorsLUT[0].value;
}
float blackPointSmoothed = blackPoint;
float whitePointSmoothed = whitePoint;
// We are not smoothing the raw data but the rise.
for (int i = 0; i < elevation.Length; i++)
{
elevation[i] = factorsLUT[i + 1].value - factorsLUT[i].value;
totalElevation += elevation[i];
if (factorsLUT[i + 1].value > whitePoint)
{
whitePoint = factorsLUT[i + 1].value;
}
if (factorsLUT[i + 1].value < blackPoint)
{
blackPoint = factorsLUT[i + 1].value;
}
}
double averageValue = 0;
double averageDivisor = 0;
float invertedSmoothIntensity = 1 - smoothIntensity;
float currentRealValueWithSmoothing = factorsLUT[0].value;
FloatIssetable[] factorsLUTSmoothed = new FloatIssetable[factorsLUT.Length];
for (int i = 0; i < 255; i++)
{
if (i == 0)
{
// let's say radius 5
// goes up to 4, so: 0 1 2 3 4 5
for (int a = 0; a <= smoothradius; a++)
{
averageValue += elevation[a];
averageDivisor += 1;
}
}
else
{
// i == 5
// 0 1 2 3 4 5
if (i <= smoothradius)
{
averageValue += elevation[0];
averageDivisor++;
}
else
{
// i == 6 : 0 1 2 3 4 5 6
// i-5 = 1. i-5-1 = 0
averageValue -= elevation[i - (smoothradius - 1)];
averageDivisor--;
}
// i + 5 = 254 : i == 249: 249 250 251 252 253 254
if (i + smoothradius < 255)
{
averageValue += elevation[i + smoothradius];
averageDivisor++;
}
else
{
averageValue -= elevation[254];
averageDivisor--;
}
}
elevationSmoothed[i] = (float)(invertedSmoothIntensity * elevation[i] + smoothIntensity * (averageValue / averageDivisor));
totalElevationSmoothed += elevationSmoothed[i];
currentRealValueWithSmoothing += elevationSmoothed[i];
if (currentRealValueWithSmoothing > whitePointSmoothed)
{
whitePointSmoothed = currentRealValueWithSmoothing;
}
if (currentRealValueWithSmoothing < blackPointSmoothed)
{
blackPointSmoothed = currentRealValueWithSmoothing;
}
}
// Need a last pass to make sure blacks and whites are still the same, thus:
float scaleFactor = (whitePointSmoothed - blackPointSmoothed) / (whitePoint - blackPoint);
for (int i = 0; i < 255; i++)
{
elevationSmoothed[i] /= scaleFactor;
}
// Transfer back to FactorsLUT
for (int i = 0; i < 255; i++)
{
factorsLUT[i + 1].value = factorsLUT[i].value + elevationSmoothed[i];
}
}
// 6. APPLY LUT
for (int y = 0; y < height; y++)
{
strideHereTest = strideTest * y;
for (int x = 0; x < width; x++) // 4 bc RGBA
{
xX4 = x * 4;
offsetHereTest = strideHereTest + xX4;
testLuma = (int)Math.Max(0, Math.Min(sixteenBitMax, (((float)testImageData[offsetHereTest]) * 0.11f + 0.59f * ((float)testImageData[offsetHereTest + 1]) + 0.3f * ((float)testImageData[offsetHereTest + 2]))));
hereFactor = factorsLUT[(int)testLuma].value;
output[offsetHereTest] = (float)testImageData[offsetHereTest] * hereFactor;
output[offsetHereTest + 1] = (float)testImageData[offsetHereTest + 1] * hereFactor;
output[offsetHereTest + 2] = (float)testImageData[offsetHereTest + 2] * hereFactor;
output[offsetHereTest + 3] = (float)testImageData[offsetHereTest + 3];
}
}
return(new FloatImage(output, strideTest, width, height, testImage.pixelFormat));
}