Mega Code Archive
Calculate the RBG projection
<![CDATA[
namespace EyeOpen.Imaging
{
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
/// <summary>
/// An utility class to do simple image processing.
/// </summary>
public static class ImageUtility
{
/// <summary>
/// Resize an image in high resolution
/// </summary>
/// <param name="bitmap">The image to resize.</param>
/// <param name="width">The expected width.</param>
/// <param name="height">the expected height.</param>
/// <returns></returns>
public static Bitmap ResizeBitmap(Bitmap bitmap, int width, int height)
{
var result = new Bitmap(width, height);
using (var graphic = Graphics.FromImage((System.Drawing.Image)result))
{
graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
graphic.DrawImage(bitmap, 0, 0, width - 1, height - 1);
}
return result;
}
/// <summary>
/// Calculate the RBG projection.
/// </summary>
/// <param name="bitmap">The image to process.</param>
/// <returns>Return horizontal RGB projection in value [0] and vertical RGB projection in value [1].</returns>
public static double[][] GetRgbProjections(Bitmap bitmap)
{
var width = bitmap.Width - 1;
var height = bitmap.Width - 1;
var horizontalProjection = new double[width];
var verticalProjection = new double[height];
var bitmapData1 = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
unsafe
{
var imagePointer1 = (byte*)bitmapData1.Scan0;
for (var y = 0; y < height; y++)
{
for (var x = 0; x < width; x++)
{
var blu = imagePointer1[0];
var green = imagePointer1[1];
var red = imagePointer1[2];
int luminosity = (byte)(((0.2126 * red) + (0.7152 * green)) + (0.0722 * blu));
horizontalProjection[x] += luminosity;
verticalProjection[y] += luminosity;
imagePointer1 += 4;
}
imagePointer1 += bitmapData1.Stride - (bitmapData1.Width * 4);
}
}
MaximizeScale(ref horizontalProjection, height);
MaximizeScale(ref verticalProjection, width);
var projections =
new[]
{
horizontalProjection,
verticalProjection
};
bitmap.UnlockBits(bitmapData1);
return projections;
}
/// <summary>
/// Optimize the range of values.
/// </summary>
/// <param name="projection">The array to process.</param>
/// <param name="max">The max value for the elements.</param>
private static void MaximizeScale(ref double[] projection, double max)
{
var minValue = double.MaxValue;
var maxValue = double.MinValue;
for (var i = 0; i < projection.Length; i++)
{
if (projection[i] > 0)
{
projection[i] = projection[i] / max;
}
if (projection[i] < minValue)
{
minValue = projection[i];
}
if (projection[i] > maxValue)
{
maxValue = projection[i];
}
}
if (maxValue == 0)
{
return;
}
for (var i = 0; i < projection.Length; i++)
{
if (maxValue == 255)
{
projection[i] = 1;
}
else
{
projection[i] = (projection[i] - minValue) / (maxValue - minValue);
}
}
}
}
}
]]>