public static UBitmap FromImage(Image image)
{
var bmp = new Bitmap(image);
var ubmp = new UBitmap(image.Width, image.Height);
for (var y = 0; y < image.Height - 1; y++)
{
for (var x = 0; x < image.Width - 1; x++)
{
ubmp.SetPixel(x, y, bmp.GetPixel(x, y));
}
}
return(ubmp);
}
/// <summary>
/// Detect the edges in the image
/// </summary>
/// <param name="image"></param>
/// <returns></returns>
public static Image DetectEdges(this Image image)
{
//Downscale or Upscale
//image = image.Resize(500);
//image = image.MakeGrayscale3();
var bmp = UBitmap.FromImage(image);
var target = new UBitmap(bmp.Width, bmp.Height);
//var pixels = new List<Point>();
//Iterate through each pixel in the image row by row
//y is row
for (var y = 0; y < bmp.Height - 1; y++)
{
//x is column
for (var x = 0; x < bmp.Width - 1; x++)
{
//Get the pixel represented at the (x,y) coordinates
var pixelColor = bmp.GetPixel(x, y);
//get the argb color code of the pixel
var pixel = pixelColor.ToArgb();
//make sure the pixel is not the first one on either of X and Y planes, because we need to process neighbouring pixels
if (x != 0 && y != 0)
{
//Pixel directly above this one, the names should be self explanatory, so not going into details of those.
var top = bmp.GetPixel(x, y - 1).ToArgb();
var left = bmp.GetPixel(x - 1, y).ToArgb();
var bottom = bmp.GetPixel(x, y + 1).ToArgb();
var right = bmp.GetPixel(x + 1, y).ToArgb();
var topLeft = bmp.GetPixel(x - 1, y - 1).ToArgb();
var topRight = bmp.GetPixel(x + 1, y - 1).ToArgb();
var bottomLeft = bmp.GetPixel(x - 1, y + 1).ToArgb();
var bottomRight = bmp.GetPixel(x + 1, y + 1).ToArgb();
//Take all of the neighbouring pixels into an array for easier processing
var colors = new int[] { top, left, bottom, right, topLeft, topRight, bottomLeft, bottomRight };
//check whether this pixel is worthy of being added to the 'edge' detection
var shouldAdd = colors.Select(color =>
{
//the pixels to compare
//pixel is this pixel, color is the neighbouring one
var compare = new int[] { pixel, color };
//Find the difference between the two
var difference = compare.Max() - compare.Min();
//Find the percentage difference between the two
//Also we need a positive number, whether they turn negative or positive,
//so we convert any negatives into positives and leave positives untouched
//If that didn't make any sense, you should read about 'Math.Abs' (Absolute) function
//There should be tonnes of articles,answers and explanations on the internet
var percentageDifference = Math.Abs(((double)difference / -1.0d) * 100d);
//Check if the difference is atleast 50%, if so, we assume it as an edge
return(percentageDifference >= 50.0d);
}).Any(b => b);
if (shouldAdd)
{
//Add the pixel as an edge
target.SetPixel(x, y, pixelColor);
}
}
}
}
//We cannot have any messy values in the image's pixels so we convert all of them into white color (-1 is white)
for (var i = 0; i < target.Bits.Length; i++)
{
if (target.Bits[i] == 0)
{
target.Bits[i] = -1;
}
}
//return the edge detected image
return(target.Bitmap);
}
