/// <summary>
/// Convert from HSL to RGB color space.
/// </summary>
///
/// <param name="hsl">Source color in <b>HSL</b> color space.</param>
/// <param name="rgb">Destination color in <b>RGB</b> color space.</param>
///
public static void ToRGB(HSL hsl, RGB rgb)
{
if (hsl.Saturation == 0)
{
// gray values
rgb.Red = rgb.Green = rgb.Blue = (byte)(hsl.Luminance * 255);
}
else
{
float v1, v2;
float hue = (float)hsl.Hue / 360;
v2 = (hsl.Luminance < 0.5) ?
(hsl.Luminance * (1 + hsl.Saturation)) :
((hsl.Luminance + hsl.Saturation) - (hsl.Luminance * hsl.Saturation));
v1 = 2 * hsl.Luminance - v2;
rgb.Red = (byte)(255 * Hue_2_RGB(v1, v2, hue + (1.0f / 3)));
rgb.Green = (byte)(255 * Hue_2_RGB(v1, v2, hue));
rgb.Blue = (byte)(255 * Hue_2_RGB(v1, v2, hue - (1.0f / 3)));
}
rgb.Alpha = 255;
}
/// <summary>
/// Paint the controls.
/// </summary>
///
/// <param name="e">Paint event arguments.</param>
///
protected override void OnPaint(PaintEventArgs e)
{
Graphics g = e.Graphics;
Rectangle rc = this.ClientRectangle;
Rectangle rcPie;
Brush brush;
RGB rgb = new RGB();
HSL hsl = new HSL();
// get pie rectangle
rcPie = new Rectangle(4, 4, System.Math.Min(rc.Right, rc.Bottom) - 8, System.Math.Min(rc.Right, rc.Bottom) - 8);
// init HSL value
hsl.Luminance = 0.5f;
hsl.Saturation = 1.0f;
if (type == HuePickerType.Value)
{
// draw HSL pie
for (int i = 0; i < 360; i++)
{
hsl.Hue = i;
// convert from HSL to RGB
Accord.Imaging.HSL.ToRGB(hsl, rgb);
// create brush
brush = new SolidBrush(rgb.Color);
// draw one hue value
g.FillPie(brush, rcPie, -i, -1);
brush.Dispose();
}
}
else
{
// draw HSL pie
for (int i = 0; i < 360; i++)
{
if (
((min < max) && (i >= min) && (i <= max)) ||
((min > max) && ((i >= min) || (i <= max))))
{
hsl.Hue = i;
// convert from HSL to RGB
Accord.Imaging.HSL.ToRGB(hsl, rgb);
// create brush
brush = new SolidBrush(rgb.Color);
}
else
{
brush = new SolidBrush(Color.FromArgb(128, 128, 128));
}
// draw one hue value
g.FillPie(brush, rcPie, -i, -1);
brush.Dispose();
}
}
//
double halfWidth = (double)rcPie.Width / 2;
double angleRad = -min * System.Math.PI / 180;
double angleCos = System.Math.Cos(angleRad);
double angleSin = System.Math.Sin(angleRad);
double x = halfWidth * angleCos;
double y = halfWidth * angleSin;
ptCenter.X = rcPie.Left + (int)(halfWidth);
ptCenter.Y = rcPie.Top + (int)(halfWidth);
ptMin.X = rcPie.Left + (int)(halfWidth + x);
ptMin.Y = rcPie.Top + (int)(halfWidth + y);
// draw MIN pointer
g.FillEllipse(blackBrush,
rcPie.Left + (int)(halfWidth + x) - 4,
rcPie.Top + (int)(halfWidth + y) - 4,
8, 8);
g.DrawLine(blackPen, ptCenter, ptMin);
// check picker type
if (type == HuePickerType.Range)
{
angleRad = -max * System.Math.PI / 180;
angleCos = System.Math.Cos(angleRad);
angleSin = System.Math.Sin(angleRad);
x = halfWidth * angleCos;
y = halfWidth * angleSin;
ptMax.X = rcPie.Left + (int)(halfWidth + x);
ptMax.Y = rcPie.Top + (int)(halfWidth + y);
// draw MAX pointer
g.FillEllipse(whiteBrush,
rcPie.Left + (int)(halfWidth + x) - 4,
rcPie.Top + (int)(halfWidth + y) - 4,
8, 8);
g.DrawLine(whitePen, ptCenter, ptMax);
}
base.OnPaint(e);
}
// Gather statistics for the specified image
private unsafe void ProcessImage(UnmanagedImage image, byte *mask, int maskLineSize)
{
// get image dimension
int width = image.Width;
int height = image.Height;
pixels = pixelsWithoutBlack = 0;
int[] s = new int[256];
int[] l = new int[256];
int[] swb = new int[256];
int[] lwb = new int[256];
RGB rgb = new RGB();
HSL hsl = new HSL();
int pixelSize = (image.PixelFormat == PixelFormat.Format24bppRgb) ? 3 : 4;
int offset = image.Stride - width * pixelSize;
int maskOffset = maskLineSize - width;
// do the job
byte *p = (byte *)image.ImageData.ToPointer();
if (mask == null)
{
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, p += pixelSize)
{
rgb.Red = p[RGB.R];
rgb.Green = p[RGB.G];
rgb.Blue = p[RGB.B];
// convert to HSL color space
Accord.Imaging.HSL.FromRGB(rgb, ref hsl);
s[(int)(hsl.Saturation * 255)]++;
l[(int)(hsl.Luminance * 255)]++;
pixels++;
if (hsl.Luminance != 0.0)
{
swb[(int)(hsl.Saturation * 255)]++;
lwb[(int)(hsl.Luminance * 255)]++;
pixelsWithoutBlack++;
}
}
p += offset;
}
}
else
{
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, p += pixelSize, mask++)
{
if (*mask == 0)
{
continue;
}
rgb.Red = p[RGB.R];
rgb.Green = p[RGB.G];
rgb.Blue = p[RGB.B];
// convert to HSL color space
Accord.Imaging.HSL.FromRGB(rgb, ref hsl);
s[(int)(hsl.Saturation * 255)]++;
l[(int)(hsl.Luminance * 255)]++;
pixels++;
if (hsl.Luminance != 0.0)
{
swb[(int)(hsl.Saturation * 255)]++;
lwb[(int)(hsl.Luminance * 255)]++;
pixelsWithoutBlack++;
}
}
p += offset;
mask += maskOffset;
}
}
// create histograms
saturation = new ContinuousHistogram(s, new Range(0, 1));
luminance = new ContinuousHistogram(l, new Range(0, 1));
saturationWithoutBlack = new ContinuousHistogram(swb, new Range(0, 1));
luminanceWithoutBlack = new ContinuousHistogram(lwb, new Range(0, 1));
}
/// <summary>
/// Creates a color histogram discarding low intensity colors
/// </summary>
///
private unsafe float[] createHistogram(UnmanagedImage frame, Rectangle area)
{
int width = frame.Width;
int height = frame.Height;
int stride = frame.Stride;
int pixelSize = Bitmap.GetPixelFormatSize(frame.PixelFormat) / 8;
int offset = stride - area.Width * pixelSize;
float[] histogram = new float[histogramSize];
// stay inside the image
int areaX = Math.Max(area.X, 0);
int areaY = Math.Max(area.Y, 0);
int areaWidth = Math.Min(area.Width, width - areaX);
int areaHeight = Math.Min(area.Height, height - areaY);
if (mode == CamshiftMode.HSL)
{
// Process as HSL
HSL hsl = new HSL();
RGB rgb = new RGB();
byte* src = (byte*)frame.ImageData.ToPointer() + areaX * pixelSize + areaY * stride;
for (int y = 0; y < areaHeight; y++)
{
for (int x = 0; x < areaWidth; x++, src += 3)
{
rgb.Red = (*(src + RGB.R));
rgb.Green = (*(src + RGB.G));
rgb.Blue = (*(src + RGB.B));
Accord.Imaging.HSL.FromRGB(rgb, hsl);
if ((hsl.Saturation >= hslSaturation.Min) && (hsl.Saturation <= hslSaturation.Max) &&
(hsl.Luminance >= hslLuminance.Min) && (hsl.Luminance <= hslLuminance.Max))
histogram[hsl.Hue] += 1;
}
src += offset;
}
}
else if (mode == CamshiftMode.Mixed)
{
// Process in mixed mode
HSL hsl = new HSL();
RGB rgb = new RGB();
byte* src = (byte*)frame.ImageData.ToPointer() + areaX * pixelSize + areaY * stride;
for (int y = 0; y < areaHeight; y++)
{
for (int x = 0; x < areaWidth; x++, src += 3)
{
rgb.Red = (*(src + RGB.R));
rgb.Green = (*(src + RGB.G));
rgb.Blue = (*(src + RGB.B));
Accord.Imaging.HSL.FromRGB(rgb, hsl);
if ((hsl.Saturation >= hslSaturation.Min) && (hsl.Saturation <= hslSaturation.Max) &&
(hsl.Luminance >= hslLuminance.Min) && (hsl.Luminance <= hslLuminance.Max))
histogram[(int)(hsl.Hue * 10 + hsl.Saturation * 100 + hsl.Luminance * 10)] += 1;
}
src += offset;
}
}
else
{
// Process as RGB
byte* src = (byte*)frame.ImageData.ToPointer() + areaX * pixelSize + areaY * stride;
for (int y = 0; y < areaHeight; y++)
{
for (int x = 0; x < areaWidth; x++, src += 3)
{
// (small values are discarded)
int r = (int)(*(src + RGB.R)) >> 4;
int g = (int)(*(src + RGB.G)) >> 4;
int b = (int)(*(src + RGB.B)) >> 4;
histogram[256 * r + 16 * g + b] += 1;
}
src += offset;
}
}
return histogram;
}
/// <summary>
/// Image histogram back-projection.
/// </summary>
///
private unsafe void generateBackprojectionMap(UnmanagedImage frame, float[] ratioHistogram)
{
int width = frame.Width;
int height = frame.Height;
int stride = frame.Stride;
int pixelSize = Bitmap.GetPixelFormatSize(frame.PixelFormat) / 8;
int offset = stride - width * pixelSize;
fixed (float* map_ptr = map)
{
byte* src = (byte*)frame.ImageData.ToPointer();
float* dst = map_ptr;
if (mode == CamshiftMode.HSL)
{
// Process as HSL
HSL hsl = new HSL();
RGB rgb = new RGB();
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++, src += pixelSize, dst++)
{
// RGB
rgb.Red = (*(src + RGB.R));
rgb.Green = (*(src + RGB.G));
rgb.Blue = (*(src + RGB.B));
// Transform into HSL
Accord.Imaging.HSL.FromRGB(rgb, hsl);
if ((hsl.Saturation >= hslSaturation.Min) && (hsl.Saturation <= hslSaturation.Max) &&
(hsl.Luminance >= hslLuminance.Min) && (hsl.Luminance <= hslLuminance.Max))
*dst = ratioHistogram[hsl.Hue];
else *dst = 0;
}
src += offset;
}
}
else if (mode == CamshiftMode.Mixed)
{
// Process in mixed mode
HSL hsl = new HSL();
RGB rgb = new RGB();
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++, src += pixelSize, dst++)
{
// RGB
rgb.Red = (*(src + RGB.R));
rgb.Green = (*(src + RGB.G));
rgb.Blue = (*(src + RGB.B));
// Transform into HSL
Accord.Imaging.HSL.FromRGB(rgb, hsl);
if ((hsl.Saturation >= hslSaturation.Min) && (hsl.Saturation <= hslSaturation.Max) &&
(hsl.Luminance >= hslLuminance.Min) && (hsl.Luminance <= hslLuminance.Max))
*dst = ratioHistogram[(int)(hsl.Hue * 10 + hsl.Saturation * 100 + hsl.Luminance * 10)];
else *dst = 0;
}
src += offset;
}
}
else
{
// Process as RGB
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++, src += pixelSize, dst++)
{
// RGB
int r = (int)(*(src + RGB.R)) >> 4;
int g = (int)(*(src + RGB.G)) >> 4;
int b = (int)(*(src + RGB.B)) >> 4;
*dst = ratioHistogram[256 * r + 16 * g + b];
}
src += offset;
}
}
}
}
/// <summary>
/// Convert from HSL to RGB color space.
/// </summary>
///
/// <param name="hsl">Source color in <b>HSL</b> color space.</param>
/// <param name="rgb">Destination color in <b>RGB</b> color space.</param>
///
public static void ToRGB(HSL hsl, RGB rgb)
{
if (hsl.Saturation == 0)
{
// gray values
rgb.Red = rgb.Green = rgb.Blue = (byte)(hsl.Luminance * 255);
}
else
{
float v1, v2;
float hue = (float)hsl.Hue / 360;
v2 = (hsl.Luminance < 0.5) ?
(hsl.Luminance * (1 + hsl.Saturation)) :
((hsl.Luminance + hsl.Saturation) - (hsl.Luminance * hsl.Saturation));
v1 = 2 * hsl.Luminance - v2;
rgb.Red = (byte)(255 * Hue_2_RGB(v1, v2, hue + (1.0f / 3)));
rgb.Green = (byte)(255 * Hue_2_RGB(v1, v2, hue));
rgb.Blue = (byte)(255 * Hue_2_RGB(v1, v2, hue - (1.0f / 3)));
}
rgb.Alpha = 255;
}
/// <summary>
/// Convert from RGB to HSL color space.
/// </summary>
///
/// <param name="rgb">Source color in <b>RGB</b> color space.</param>
///
/// <returns>Returns <see cref="HSL"/> instance, which represents converted color value.</returns>
///
public static HSL FromRGB(RGB rgb)
{
HSL hsl = new HSL();
FromRGB(rgb, hsl);
return hsl;
}
/// <summary>
/// Convert from RGB to HSL color space.
/// </summary>
///
/// <param name="rgb">Source color in <b>RGB</b> color space.</param>
/// <param name="hsl">Destination color in <b>HSL</b> color space.</param>
///
/// <remarks><para>See <a href="http://en.wikipedia.org/wiki/HSI_color_space#Conversion_from_RGB_to_HSL_or_HSV">HSL and HSV Wiki</a>
/// for information about the algorithm to convert from RGB to HSL.</para></remarks>
///
public static void FromRGB(RGB rgb, HSL hsl)
{
float r = (rgb.Red / 255.0f);
float g = (rgb.Green / 255.0f);
float b = (rgb.Blue / 255.0f);
float min = Math.Min(Math.Min(r, g), b);
float max = Math.Max(Math.Max(r, g), b);
float delta = max - min;
// get luminance value
hsl.Luminance = (max + min) / 2;
if (delta == 0)
{
// gray color
hsl.Hue = 0;
hsl.Saturation = 0.0f;
}
else
{
// get saturation value
hsl.Saturation = (hsl.Luminance <= 0.5) ? (delta / (max + min)) : (delta / (2 - max - min));
// get hue value
float hue;
if (r == max)
{
hue = ((g - b) / 6) / delta;
}
else if (g == max)
{
hue = (1.0f / 3) + ((b - r) / 6) / delta;
}
else
{
hue = (2.0f / 3) + ((r - g) / 6) / delta;
}
// correct hue if needed
if (hue < 0)
hue += 1;
if (hue > 1)
hue -= 1;
hsl.Hue = (int)(hue * 360);
}
}
// Gather statistics for the specified image
private unsafe void ProcessImage(UnmanagedImage image, byte* mask, int maskLineSize)
{
// get image dimension
int width = image.Width;
int height = image.Height;
pixels = pixelsWithoutBlack = 0;
int[] s = new int[256];
int[] l = new int[256];
int[] swb = new int[256];
int[] lwb = new int[256];
RGB rgb = new RGB();
HSL hsl = new HSL();
int pixelSize = (image.PixelFormat == PixelFormat.Format24bppRgb) ? 3 : 4;
int offset = image.Stride - width * pixelSize;
int maskOffset = maskLineSize - width;
// do the job
byte* p = (byte*)image.ImageData.ToPointer();
if (mask == null)
{
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, p += pixelSize)
{
rgb.Red = p[RGB.R];
rgb.Green = p[RGB.G];
rgb.Blue = p[RGB.B];
// convert to HSL color space
Accord.Imaging.HSL.FromRGB(rgb, hsl);
s[(int)(hsl.Saturation * 255)]++;
l[(int)(hsl.Luminance * 255)]++;
pixels++;
if (hsl.Luminance != 0.0)
{
swb[(int)(hsl.Saturation * 255)]++;
lwb[(int)(hsl.Luminance * 255)]++;
pixelsWithoutBlack++;
}
}
p += offset;
}
}
else
{
// for each line
for (int y = 0; y < height; y++)
{
// for each pixel
for (int x = 0; x < width; x++, p += pixelSize, mask++)
{
if (*mask == 0)
continue;
rgb.Red = p[RGB.R];
rgb.Green = p[RGB.G];
rgb.Blue = p[RGB.B];
// convert to HSL color space
Accord.Imaging.HSL.FromRGB(rgb, hsl);
s[(int)(hsl.Saturation * 255)]++;
l[(int)(hsl.Luminance * 255)]++;
pixels++;
if (hsl.Luminance != 0.0)
{
swb[(int)(hsl.Saturation * 255)]++;
lwb[(int)(hsl.Luminance * 255)]++;
pixelsWithoutBlack++;
}
}
p += offset;
mask += maskOffset;
}
}
// create histograms
saturation = new ContinuousHistogram(s, new Range(0, 1));
luminance = new ContinuousHistogram(l, new Range(0, 1));
saturationWithoutBlack = new ContinuousHistogram(swb, new Range(0, 1));
luminanceWithoutBlack = new ContinuousHistogram(lwb, new Range(0, 1));
}