// Process specified image trying to recognize counter's image
public void Process(Bitmap image, IImageProcessingLog log)
{
log.AddMessage("Image size: " + image.Width + " x " + image.Height);
// 1 - Grayscale
Bitmap grayImage = Grayscale.CommonAlgorithms.BT709.Apply(image);
log.AddImage("Grayscale", grayImage);
// 2 - Edge detection
DifferenceEdgeDetector edgeDetector = new DifferenceEdgeDetector( );
Bitmap edges = edgeDetector.Apply(grayImage);
log.AddImage("Edges", edges);
// 3 - Threshold edges
Threshold thresholdFilter = new Threshold(40);
thresholdFilter.ApplyInPlace(edges);
log.AddImage("Thresholded Edges", edges);
// 4 - Blob Counter
BlobCounter blobCounter = new BlobCounter( );
blobCounter.MinHeight = 32;
blobCounter.MinWidth = 32;
blobCounter.FilterBlobs = true;
blobCounter.ObjectsOrder = ObjectsOrder.Size;
blobCounter.ProcessImage(edges);
Blob[] blobs = blobCounter.GetObjectsInformation( );
// create copy of source image, so we could draw on it
Bitmap imageCopy = AForge.Imaging.Image.Clone(image);
BitmapData imageData = imageCopy.LockBits(new Rectangle(0, 0, image.Width, image.Height),
ImageLockMode.ReadWrite, imageCopy.PixelFormat);
// lock grayscale image, so we could access it's pixel values
BitmapData grayData = grayImage.LockBits(new Rectangle(0, 0, image.Width, image.Height),
ImageLockMode.ReadOnly, grayImage.PixelFormat);
UnmanagedImage grayUI = new UnmanagedImage(grayData);
// list of found dark/black quadrilaterals surrounded by white area
List <List <IntPoint> > foundObjects = new List <List <IntPoint> >( );
// shape checker for checking quadrilaterals
SimpleShapeChecker shapeChecker = new SimpleShapeChecker( );
// 5 - check each blob
for (int i = 0, n = blobs.Length; i < n; i++)
{
List <IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
List <IntPoint> corners = null;
// does it look like a quadrilateral ?
if (shapeChecker.IsQuadrilateral(edgePoints, out corners))
{
// do some more checks to filter so unacceptable shapes
// if ( CheckIfShapeIsAcceptable( corners ) )
{
log.AddMessage("Blob size: " + blobs[i].Rectangle.Width + " x " + blobs[i].Rectangle.Height);
// get edge points on the left and on the right side
List <IntPoint> leftEdgePoints, rightEdgePoints;
blobCounter.GetBlobsLeftAndRightEdges(blobs[i], out leftEdgePoints, out rightEdgePoints);
// calculate average difference between pixel values from outside of the shape and from inside
float diff = CalculateAverageEdgesBrightnessDifference(
leftEdgePoints, rightEdgePoints, grayUI);
log.AddMessage("Avg Diff: " + diff);
// check average difference, which tells how much outside is lighter than inside on the average
if (diff > 20)
{
Drawing.Polygon(imageData, corners, Color.Red);
// add the object to the list of interesting objects for further processing
foundObjects.Add(corners);
}
}
}
}
imageCopy.UnlockBits(imageData);
grayImage.UnlockBits(grayData);
log.AddImage("Potential glyps", imageCopy);
int counter = 1;
// further processing of each potential glyph
foreach (List <IntPoint> corners in foundObjects)
{
log.AddMessage("Glyph #" + counter);
log.AddMessage(string.Format("Corners: ({0}), ({1}), ({2}), ({3})",
corners[0], corners[1], corners[2], corners[3]));
// 6 - do quadrilateral transformation
QuadrilateralTransformation quadrilateralTransformation =
new QuadrilateralTransformation(corners, 250, 250);
Bitmap transformed = quadrilateralTransformation.Apply(grayImage);
log.AddImage("Transformed #" + counter, transformed);
// 7 - otsu thresholding
OtsuThreshold otsuThresholdFilter = new OtsuThreshold( );
Bitmap transformedOtsu = otsuThresholdFilter.Apply(transformed);
log.AddImage("Transformed Otsu #" + counter, transformedOtsu);
int glyphSize = 5;
SquareBinaryGlyphRecognizer gr = new SquareBinaryGlyphRecognizer(glyphSize);
bool[,] glyphValues = gr.Recognize(transformedOtsu,
new Rectangle(0, 0, 250, 250));
log.AddImage("Glyph lines #" + counter, transformedOtsu);
// output recognize glyph to log
log.AddMessage(string.Format("glyph: {0:F2}%", gr.confidence * 100));
for (int i = 0; i < glyphSize; i++)
{
StringBuilder sb = new StringBuilder(" ");
for (int j = 0; j < glyphSize; j++)
{
sb.Append((glyphValues[i, j]) ? "1 " : "0 ");
}
log.AddMessage(sb.ToString( ));
}
counter++;
}
}
// Process specified image trying to recognize counter's image
public void Process( Bitmap image, IImageProcessingLog log )
{
log.AddMessage( "Image size: " + image.Width + " x " + image.Height );
// 1 - Grayscale
Bitmap grayImage = Grayscale.CommonAlgorithms.BT709.Apply( image );
log.AddImage( "Grayscale", grayImage );
// 2 - Edge detection
DifferenceEdgeDetector edgeDetector = new DifferenceEdgeDetector( );
Bitmap edges = edgeDetector.Apply( grayImage );
log.AddImage( "Edges", edges );
// 3 - Threshold edges
Threshold thresholdFilter = new Threshold( 40 );
thresholdFilter.ApplyInPlace( edges );
log.AddImage( "Thresholded Edges", edges );
// 4 - Blob Counter
BlobCounter blobCounter = new BlobCounter( );
blobCounter.MinHeight = 32;
blobCounter.MinWidth = 32;
blobCounter.FilterBlobs = true;
blobCounter.ObjectsOrder = ObjectsOrder.Size;
blobCounter.ProcessImage( edges );
Blob[] blobs = blobCounter.GetObjectsInformation( );
// create copy of source image, so we could draw on it
Bitmap imageCopy = AForge.Imaging.Image.Clone( image );
BitmapData imageData = imageCopy.LockBits( new Rectangle( 0, 0, image.Width, image.Height ),
ImageLockMode.ReadWrite, imageCopy.PixelFormat );
// lock grayscale image, so we could access it's pixel values
BitmapData grayData = grayImage.LockBits( new Rectangle( 0, 0, image.Width, image.Height ),
ImageLockMode.ReadOnly, grayImage.PixelFormat );
UnmanagedImage grayUI = new UnmanagedImage( grayData );
// list of found dark/black quadrilaterals surrounded by white area
List<List<IntPoint>> foundObjects = new List<List<IntPoint>>( );
// shape checker for checking quadrilaterals
SimpleShapeChecker shapeChecker = new SimpleShapeChecker( );
// 5 - check each blob
for ( int i = 0, n = blobs.Length; i < n; i++ )
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints( blobs[i] );
List<IntPoint> corners = null;
// does it look like a quadrilateral ?
if ( shapeChecker.IsQuadrilateral( edgePoints, out corners ) )
{
// do some more checks to filter so unacceptable shapes
// if ( CheckIfShapeIsAcceptable( corners ) )
{
log.AddMessage( "Blob size: " + blobs[i].Rectangle.Width + " x " + blobs[i].Rectangle.Height );
// get edge points on the left and on the right side
List<IntPoint> leftEdgePoints, rightEdgePoints;
blobCounter.GetBlobsLeftAndRightEdges( blobs[i], out leftEdgePoints, out rightEdgePoints );
// calculate average difference between pixel values from outside of the shape and from inside
float diff = CalculateAverageEdgesBrightnessDifference(
leftEdgePoints, rightEdgePoints, grayUI );
log.AddMessage( "Avg Diff: " + diff );
// check average difference, which tells how much outside is lighter than inside on the average
if ( diff > 20 )
{
Drawing.Polygon( imageData, corners, Color.Red );
// add the object to the list of interesting objects for further processing
foundObjects.Add( corners );
}
}
}
}
imageCopy.UnlockBits( imageData );
grayImage.UnlockBits( grayData );
log.AddImage( "Potential glyps", imageCopy );
int counter = 1;
// further processing of each potential glyph
foreach ( List<IntPoint> corners in foundObjects )
{
log.AddMessage( "Glyph #" + counter );
log.AddMessage( string.Format( "Corners: ({0}), ({1}), ({2}), ({3})",
corners[0], corners[1], corners[2], corners[3] ) );
// 6 - do quadrilateral transformation
QuadrilateralTransformation quadrilateralTransformation =
new QuadrilateralTransformation( corners, 250, 250 );
Bitmap transformed = quadrilateralTransformation.Apply( grayImage );
log.AddImage( "Transformed #" + counter, transformed );
// 7 - otsu thresholding
OtsuThreshold otsuThresholdFilter = new OtsuThreshold( );
Bitmap transformedOtsu = otsuThresholdFilter.Apply( transformed );
log.AddImage( "Transformed Otsu #" + counter, transformedOtsu );
int glyphSize = 5;
SquareBinaryGlyphRecognizer gr = new SquareBinaryGlyphRecognizer( glyphSize );
bool[,] glyphValues = gr.Recognize( transformedOtsu,
new Rectangle( 0, 0, 250, 250 ) );
log.AddImage( "Glyph lines #" + counter, transformedOtsu );
// output recognize glyph to log
log.AddMessage( string.Format( "glyph: {0:F2}%", gr.confidence * 100 ) );
for ( int i = 0; i < glyphSize; i++ )
{
StringBuilder sb = new StringBuilder( " " );
for ( int j = 0; j < glyphSize; j++ )
{
sb.Append( ( glyphValues[i, j] ) ? "1 " : "0 " );
}
log.AddMessage( sb.ToString( ) );
}
counter++;
}
}
