/// <summary>
/// Return a Bitmap created from the given CIELab color values
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public Bitmap GetBitmapFromCIELABImage( CIELab[] s, int width, int height )
{
// create map
Bitmap b = new Bitmap( width, height, PixelFormat.Format32bppPArgb );
// iterate pixels
for( int y = 0 ; y < height ; y++ )
{
for( int x = 0 ; x < width ; x++ )
{
// get CIE XYZ mapping for pixel and then convert this to CIE Lab
double CIE_X, CIE_Y, CIE_Z;
CIELab cie = s[ y * width + x ];
RgbaHls.CIELAB_2_CIEXYZ( cie.L, cie.a, cie.b, out CIE_X, out CIE_Y, out CIE_Z );
// convert back to RGB
Color c = RgbaHls.CIEXYZ_2_RGB( CIE_X, CIE_Y, CIE_Z );
// insert into bitmap
b.SetPixel( x, y, c );
}
}
// return bitmap
return b;
}
/// <summary>
/// Return a Bitmap created from the given CIELab color values
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public Bitmap GetBitmapFromCIELABImage(CIELab[] s, int width, int height)
{
// create map
Bitmap b = new Bitmap(width, height, PixelFormat.Format32bppPArgb);
// iterate pixels
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
// get CIE XYZ mapping for pixel and then convert this to CIE Lab
double CIE_X, CIE_Y, CIE_Z;
CIELab cie = s[y * width + x];
RgbaHls.CIELAB_2_CIEXYZ(cie.L, cie.a, cie.b, out CIE_X, out CIE_Y, out CIE_Z);
// convert back to RGB
Color c = RgbaHls.CIEXYZ_2_RGB(CIE_X, CIE_Y, CIE_Z);
// insert into bitmap
b.SetPixel(x, y, c);
}
}
// return bitmap
return(b);
}
/// <summary>
/// Return and a CIE Lab color mapping of the source image. Alpha is ignored. Also returns the
/// min/max CIE L value found in the image.
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public CIELab[] GetCIELABImage(Bitmap source, out double minL, out double maxL)
{
// init L limits
minL = double.MaxValue;
maxL = double.MinValue;
// create map
CIELab[] map = new CIELab[source.Width * source.Height];
// iterate pixels
for (int y = 0; y < source.Height; y++)
{
for (int x = 0; x < source.Width; x++)
{
// get CIE XYZ mapping for pixel and then convert this to CIE Lab
double CIE_X, CIE_Y, CIE_Z;
RgbaHls.RGB_2_CIEXYZ(source.GetPixel(x, y), out CIE_X, out CIE_Y, out CIE_Z);
double CIE_L, CIE_a, CIE_b;
RgbaHls.CIEXYZ_2_CIELAB(CIE_X, CIE_Y, CIE_Z, out CIE_L, out CIE_a, out CIE_b);
// insert into map
map[y * source.Width + x] = new CIELab(CIE_L, CIE_a, CIE_b);
// update L limits
minL = Math.Min(minL, CIE_L);
maxL = Math.Max(maxL, CIE_L);
}
}
// return mapping
return(map);
}
/// <summary>
/// Create a new ( red eye removed ) image.
/// </summary>
/// <returns></returns>
public Bitmap GetNewImage(CIELab[] cieMap, double minL, double maxL, Bitmap mask)
{
// create a set of target color which are the original CIE Lab colors set to gray scales by setting a* and b* to zero and stretching the L* to
// the dynamic range of the image. This formula is used
//
// L = maxL
// ---------------------------- * ( L - minL )
// maxL - minL
//
// a = 0
// b = 0
//
CIELab[] t = new CIELab[cieMap.Length];
double r = maxL / (maxL - minL);
for (int y = 0; y < mask.Height; y++)
{
for (int x = 0; x < mask.Width; x++)
{
t[y * mask.Width + x] = new CIELab(r * (cieMap[y * mask.Width + x].L - minL), 0, 0);
}
}
// now calculate a new CIE Lab color for pixel using:
//
// pixel = t[i,j] * mask[i,j] + ( cieMap[i,j] * ( 1 - mask[i,j] ) )
//
for (int j = 0; j < mask.Height; j++)
{
for (int i = 0; i < mask.Width; i++)
{
// get normalized mask value for this pixel ( any of the RGB components will do, they should all be the same )
double m = (double)(mask.GetPixel(i, j).R) / 255.0;
// get original CIE Lab from ciemap
CIELab original = cieMap[j * mask.Width + i];
CIELab target = t[j * mask.Width + i];
// calculate new L* a* b* values using formula above
double L = target.L * m + original.L * (1 - m);
double a = target.a * m + original.a * (1 - m);
double b = target.b * m + original.b * (1 - m);
// reuse target array to hold new value for pixel ( in CIE Lab space )
t[j * mask.Width + i] = new CIELab(L, a, b);
}
}
// return new image
return(GetBitmapFromCIELABImage(t, mask.Width, mask.Height));
}
/// <summary>
/// Create a new ( red eye removed ) image.
/// </summary>
/// <returns></returns>
public Bitmap GetNewImage( CIELab[] cieMap, double minL, double maxL, Bitmap mask )
{
// create a set of target color which are the original CIE Lab colors set to gray scales by setting a* and b* to zero and stretching the L* to
// the dynamic range of the image. This formula is used
//
// L = maxL
// ---------------------------- * ( L - minL )
// maxL - minL
//
// a = 0
// b = 0
//
CIELab[] t = new CIELab[ cieMap.Length ];
double r = maxL / ( maxL - minL );
for( int y = 0 ; y < mask.Height ; y++ )
{
for( int x = 0 ; x < mask.Width ; x++ )
{
t[ y * mask.Width + x ] = new CIELab( r * ( cieMap[ y * mask.Width + x ].L - minL ) , 0, 0 );
}
}
// now calculate a new CIE Lab color for pixel using:
//
// pixel = t[i,j] * mask[i,j] + ( cieMap[i,j] * ( 1 - mask[i,j] ) )
//
for( int j = 0 ; j < mask.Height ; j++ )
{
for( int i = 0 ; i < mask.Width ; i++ )
{
// get normalized mask value for this pixel ( any of the RGB components will do, they should all be the same )
double m = (double)(mask.GetPixel( i, j ).R) / 255.0;
// get original CIE Lab from ciemap
CIELab original = cieMap[ j * mask.Width + i ];
CIELab target = t[ j * mask.Width + i ];
// calculate new L* a* b* values using formula above
double L = target.L * m + original.L * ( 1 - m );
double a = target.a * m + original.a * ( 1 - m );
double b = target.b * m + original.b * ( 1 - m );
// reuse target array to hold new value for pixel ( in CIE Lab space )
t[ j * mask.Width + i ] = new CIELab( L, a, b );
}
}
// return new image
return GetBitmapFromCIELABImage( t, mask.Width, mask.Height );
}
/// <summary>
/// Returns a bitmap of gray levels where the 'red-ness' of the original pixel determines the
/// black/white value. Black pixels are farthest from red and white pixels are closest.
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public Bitmap GetMaskImage( CIELab[] cieMap, int width, int height )
{
// get chromaticty distance map and min/max chromaticty distances
double minCD, maxCD;
double[] cdMap = GetChromaticityDistanceMap( cieMap, width, height, out minCD, out maxCD );
// create a black image of the same size
Bitmap mask = ImageUtility.CreateImage( width, height, PixelFormat.Format32bppPArgb, Color.FromArgb(255,0,0,0) );
// process each pixel
for( int y = 0 ; y < height ; y++ )
{
for( int x = 0 ; x < width ; x++ )
{
// Mask value =
//
// maxCD - chromaticty distance [x,y]
// Round( 255 * ------------------------------------- )
// maxCD - minCD
//
double temp = ( maxCD - cdMap[ y * width + x ] ) / ( maxCD - minCD );
int maskValue = (int)Math.Min( 255.0, Math.Max( 0.0, Math.Round( 255.0 * temp ) ) );
// set RGBA values
mask.SetPixel( x, y, Color.FromArgb( 255, maskValue, maskValue, maskValue ) );
}
}
// return mask image
return mask;
}
/// <summary>
/// Return and a CIE Lab color mapping of the source image. Alpha is ignored. Also returns the
/// min/max CIE L value found in the image.
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public CIELab[] GetCIELABImage( Bitmap source, out double minL, out double maxL )
{
// init L limits
minL = double.MaxValue;
maxL = double.MinValue;
// create map
CIELab[] map = new CIELab[ source.Width * source.Height ];
// iterate pixels
for( int y = 0 ; y < source.Height ; y++ )
{
for( int x = 0 ; x < source.Width ; x++ )
{
// get CIE XYZ mapping for pixel and then convert this to CIE Lab
double CIE_X, CIE_Y, CIE_Z;
RgbaHls.RGB_2_CIEXYZ( source.GetPixel( x,y ), out CIE_X, out CIE_Y, out CIE_Z );
double CIE_L, CIE_a, CIE_b;
RgbaHls.CIEXYZ_2_CIELAB( CIE_X, CIE_Y, CIE_Z, out CIE_L, out CIE_a, out CIE_b );
// insert into map
map[ y * source.Width + x ] = new CIELab( CIE_L, CIE_a, CIE_b );
// update L limits
minL = Math.Min( minL, CIE_L );
maxL = Math.Max( maxL, CIE_L );
}
}
// return mapping
return map;
}
/// <summary>
/// Given a CIELab array ( obtained with GetCIELABImage ) this calculate the chromaticity distance of
/// each pixel fro the 'typical' red eye CIELAB color. Also returns the Min/Max chromaticity distances found
/// </summary>
/// <returns></returns>
public double[] GetChromaticityDistanceMap( CIELab[] map, int width, int height, out double minDistance, out double maxDistance )
{
// initialize min/max
minDistance = double.MaxValue;
maxDistance = double.MinValue;
// create return array
double[] cdMap = new double[ width * height ];
// iterate pixels
for( int y = 0 ; y < height ; y++ )
{
for( int x = 0 ; x < width ; x++ )
{
// get distance for this pixel
double c = RgbaHls.ChromaticityDistance( map[ y * width + x ].a, kA_REDEYE, map[ y * width + x ].b, kB_REDEYE );
// assign to map
cdMap[ y * width + x ] = c;
// update min/max
minDistance = Math.Min( minDistance, c );
maxDistance = Math.Max( maxDistance, c );
}
}
// return chromaticty map
return cdMap;
}
