private unsafe BorderAnalysis AnalyzeRgb(BitmapData bitmap, Rectangle rectangle, int colorThreshold, float bucketThreshold)
{
var h = bitmap.Height;
var w = bitmap.Width;
// Stride, scan width.
var s = bitmap.Stride;
// Scan0, pointer to first scan.
var s0 = (byte *)bitmap.Scan0;
// A list of counted colors found along the rectangle border
var colors = new Dictionary <Color, int>(colorThreshold);
// A list of counted color buckets
var buckets = new Dictionary <int, int>(ColorExtensions.GetMaxColorBuckets());
// A loop of pixels along the left edge from top to bottom
for (var y = 0; y < h; y++)
{
// Pointer to current scanline
var row = s0 + y * s;
// Pixels are stored in b,g,r-order
// In this case one byte per color
var p = rectangle.Left * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
// Create a color value
var c = Color.FromArgb(r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
// A loop of pixels along the right edge from top to bottom
for (var y = 0; y < h; y++)
{
var row = s0 + y * s;
var p = (rectangle.Right - 1) * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var c = Color.FromArgb(r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
// A loop of pixels along the top edge from left to right
for (var x = 0; x < w; x++)
{
var row = s0 + rectangle.Top * s;
var p = x * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var c = Color.FromArgb(r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
// A loop of pixels along the bottom edge from left to right
for (var x = 0; x < w; x++)
{
var row = s0 + (rectangle.Bottom - 1) * s;
var p = x * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var c = Color.FromArgb(r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
return(new BorderAnalysis(colors, buckets, colorThreshold, bucketThreshold));
}
private unsafe BorderAnalysis AnalyzeArgb(BitmapData bitmap, Rectangle rectangle, int colorThreshold, float bucketThreshold)
{
var h = bitmap.Height;
var w = bitmap.Width;
var s = bitmap.Stride;
var s0 = (byte *)bitmap.Scan0;
var colors = new Dictionary <Color, int>(colorThreshold);
var buckets = new Dictionary <int, int>(ColorExtensions.GetMaxColorBuckets());
unchecked
{
for (var y = 0; y < h; y++)
{
var row = s0 + y * s;
var p = rectangle.Left * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var a = row[p + 3];
var c = a == 0 ? Color.Transparent : Color.FromArgb(a, r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
for (var y = 0; y < h; y++)
{
var row = s0 + y * s;
var p = (rectangle.Right - 1) * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var a = row[p + 3];
var c = a == 0 ? Color.Transparent : Color.FromArgb(a, r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
for (var x = 0; x < w; x++)
{
var row = s0 + rectangle.Top * s;
var p = x * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var a = row[p + 3];
var c = a == 0 ? Color.Transparent : Color.FromArgb(a, r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
for (var x = 0; x < w; x++)
{
var row = s0 + (rectangle.Bottom - 1) * s;
var p = x * BytesPerPixel;
var b = row[p];
var g = row[p + 1];
var r = row[p + 2];
var a = row[p + 3];
var c = a == 0 ? Color.Transparent : Color.FromArgb(a, r, g, b);
var ce = colors.ContainsKey(c);
if (ce)
{
colors[c]++;
}
else if (colors.Count < colorThreshold)
{
colors.Add(c, 1);
}
if (ce || colors.Count >= colorThreshold)
{
var cb = c.ToColorBucket();
if (buckets.ContainsKey(cb))
{
buckets[cb]++;
}
else
{
buckets.Add(cb, 1);
}
}
}
}
return(new BorderAnalysis(colors, buckets, colorThreshold, bucketThreshold));
}
