How To Convert C# Code into Android (Motion Detection ) - feature-detection

Question

public class MotionDetector1 : IMotionDetector
{
private IFilter grayscaleFilter = new GrayscaleBT709( );
private Difference differenceFilter = new Difference( );
private Threshold thresholdFilter = new Threshold( 15 );
private IFilter erosionFilter = new Erosion( );
private Merge mergeFilter = new Merge( );
private IFilter extrachChannel = new ExtractChannel( RGB.R );
private ReplaceChannel replaceChannel = new ReplaceChannel( RGB.R, null );
private Bitmap backgroundFrame;
private BitmapData bitmapData;
private bool calculateMotionLevel = false;
private int width; // image width
private int height; // image height
private int pixelsChanged;
// Motion level calculation - calculate or not motion level
public bool MotionLevelCalculation
{
get { return calculateMotionLevel; }
set { calculateMotionLevel = value; }
}
// Motion level - amount of changes in percents
public double MotionLevel
{
get { return (double) pixelsChanged / ( width * height ); }
}
// Constructor
public MotionDetector1( )
{
}
// Reset detector to initial state
public void Reset( )
{
if ( backgroundFrame != null )
{
backgroundFrame.Dispose( );
backgroundFrame = null;
}
}
// Process new frame
public void ProcessFrame( ref Bitmap image )
{
if ( backgroundFrame == null )
{
// create initial backgroung image
backgroundFrame = grayscaleFilter.Apply( image );
// get image dimension
width = image.Width;
height = image.Height;
// just return for the first time
return;
}
Bitmap tmpImage;
// apply the grayscale file
tmpImage = grayscaleFilter.Apply( image );
// set backgroud frame as an overlay for difference filter
differenceFilter.OverlayImage = backgroundFrame;
// apply difference filter
Bitmap tmpImage2 = differenceFilter.Apply( tmpImage );
// lock the temporary image and apply some filters on the locked data
bitmapData = tmpImage2.LockBits( new Rectangle( 0, 0, width, height ),
ImageLockMode.ReadWrite, PixelFormat.Format8bppIndexed );
// threshold filter
thresholdFilter.ApplyInPlace( bitmapData );
// erosion filter
Bitmap tmpImage3 = erosionFilter.Apply( bitmapData );
// unlock temporary image
tmpImage2.UnlockBits( bitmapData );
tmpImage2.Dispose( );
// calculate amount of changed pixels
pixelsChanged = ( calculateMotionLevel ) ?
CalculateWhitePixels( tmpImage3 ) : 0;
// dispose old background
backgroundFrame.Dispose( );
// set backgound to current
backgroundFrame = tmpImage;
// extract red channel from the original image
Bitmap redChannel = extrachChannel.Apply( image );
// merge red channel with moving object
mergeFilter.OverlayImage = tmpImage3;
Bitmap tmpImage4 = mergeFilter.Apply( redChannel );
redChannel.Dispose( );
tmpImage3.Dispose( );
// replace red channel in the original image
replaceChannel.ChannelImage = tmpImage4;
Bitmap tmpImage5 = replaceChannel.Apply( image );
tmpImage4.Dispose( );
image.Dispose( );
image = tmpImage5;
}
// Calculate white pixels
private int CalculateWhitePixels( Bitmap image )
{
int count = 0;
// lock difference image
BitmapData data = image.LockBits( new Rectangle( 0, 0, width, height ),
ImageLockMode.ReadOnly, PixelFormat.Format8bppIndexed );
int offset = data.Stride - width;
unsafe
{
byte * ptr = (byte *) data.Scan0.ToPointer( );
for ( int y = 0; y < height; y++ )
{
for ( int x = 0; x < width; x++, ptr++ )
{
count += ( (*ptr) >> 7 );
}
ptr += offset;
}
}
// unlock image
image.UnlockBits( data );
return count;
}
}
}