Color filtering.
The filter filters pixels inside/outside of specified RGB color range - it keeps pixels with colors inside/outside of specified range and fills the rest with
The filter accepts 24 and 32 bpp color images for processing.
Sample usage:
// create filter ColorFiltering filter = new ColorFiltering( ); // set color ranges to keep filter.Red = new IntRange( 100, 255 ); filter.Green = new IntRange( 0, 75 ); filter.Blue = new IntRange( 0, 75 ); // apply the filter filter.ApplyInPlace( image ); Initial image:
Result image:
private void SetFilter()
{
ImageType = ImageTypes.Rgb32bpp;
Af.ColorFiltering newFilter = new Af.ColorFiltering();
newFilter.FillColor = new Accord.Imaging.RGB(color);
newFilter.Red = new Accord.IntRange((int)Remap(red.T0, 0, 255), (int)Remap(red.T1, 0, 255));
newFilter.Green = new Accord.IntRange((int)Remap(green.T0, 0, 255), (int)Remap(green.T1, 0, 255));
newFilter.Blue = new Accord.IntRange((int)Remap(blue.T0, 0, 255), (int)Remap(blue.T1, 0, 255));
newFilter.FillOutsideRange = outside;
imageFilter = newFilter;
}
// Process image
private void ProcessImage(Bitmap bitmap)
{
// lock image
BitmapData bitmapData = bitmap.LockBits(
new Rectangle(0, 0, bitmap.Width, bitmap.Height),
ImageLockMode.ReadWrite, bitmap.PixelFormat);
// step 1 - turn background to black
ColorFiltering colorFilter = new ColorFiltering();
colorFilter.Red = new IntRange(0, 64);
colorFilter.Green = new IntRange(0, 64);
colorFilter.Blue = new IntRange(0, 64);
colorFilter.FillOutsideRange = false;
colorFilter.ApplyInPlace(bitmapData);
// step 2 - locating objects
BlobCounter blobCounter = new BlobCounter();
blobCounter.FilterBlobs = true;
blobCounter.MinHeight = 5;
blobCounter.MinWidth = 5;
blobCounter.ProcessImage(bitmapData);
Blob[] blobs = blobCounter.GetObjectsInformation();
bitmap.UnlockBits(bitmapData);
// step 3 - check objects' type and highlight
SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
Graphics g = Graphics.FromImage(bitmap);
Pen yellowPen = new Pen(Color.Yellow, 2); // circles
Pen redPen = new Pen(Color.Red, 2); // quadrilateral
Pen brownPen = new Pen(Color.Brown, 2); // quadrilateral with known sub-type
Pen greenPen = new Pen(Color.Green, 2); // known triangle
Pen bluePen = new Pen(Color.Blue, 2); // triangle
for (int i = 0, n = blobs.Length; i < n; i++)
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
Accord.Point center;
float radius;
// is circle ?
if (shapeChecker.IsCircle(edgePoints, out center, out radius))
{
g.DrawEllipse(yellowPen,
(float)(center.X - radius), (float)(center.Y - radius),
(float)(radius * 2), (float)(radius * 2));
}
else
{
List<IntPoint> corners;
// is triangle or quadrilateral
if (shapeChecker.IsConvexPolygon(edgePoints, out corners))
{
// get sub-type
PolygonSubType subType = shapeChecker.CheckPolygonSubType(corners);
Pen pen;
if (subType == PolygonSubType.Unknown)
{
pen = (corners.Count == 4) ? redPen : bluePen;
}
else
{
pen = (corners.Count == 4) ? brownPen : greenPen;
}
g.DrawPolygon(pen, ToPointsArray(corners));
}
}
}
yellowPen.Dispose();
redPen.Dispose();
greenPen.Dispose();
bluePen.Dispose();
brownPen.Dispose();
g.Dispose();
// put new image to clipboard
Clipboard.SetDataObject(bitmap);
// and to picture box
pictureBox.Image = bitmap;
UpdatePictureBoxPosition();
}
