BitmapUtil.java

package org.mots.haxsync.utilities;

import java.io.ByteArrayOutputStream;

import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.media.FaceDetector;
import android.provider.ContactsContract.DisplayPhoto;
import android.util.Log;

public class BitmapUtil {
	
	public static int getMaxSize(Context context) {
		  // Note that this URI is safe to call on the UI thread.
		  Cursor c = context.getContentResolver().query(DisplayPhoto.CONTENT_MAX_DIMENSIONS_URI,
		      new String[]{ DisplayPhoto.DISPLAY_MAX_DIM }, null, null, null);
		  try {
		    c.moveToFirst();
		    return c.getInt(0);
		  } finally {
		    c.close();
		  }
		}
	
	private static Bitmap scale(Bitmap in, int size){
		int width = in.getWidth();
		int height = in.getHeight();
		float scalew;
		float scaleh;
		Matrix matrix = new Matrix();
		//scale smaller axis to size (if necessary)
		if (width > height){
			scaleh = (float) size / height;
			scalew = scaleh;
			if ((width * scalew) % 2 != 0){
				scalew = ((width * scalew) + 1) / (float) width;
			}
			
		}else{
			scalew = (float) size / width;
			scaleh = scalew;
			if ((height * scaleh) % 2 != 0){
				scaleh = ((height * scaleh) + 1) / (float) height;
			}
		}
		Log.i("RESIZING", "old width: " + width + "old height: " + height + "new size: " + size);
		matrix.postScale(scalew, scaleh);
		Bitmap scaledPic = Bitmap.createBitmap(in, 0, 0, width, height, matrix, true);
		return scaledPic;		
	}
	
	private static PointF findFaceMid(Bitmap in){
		PointF mid = new PointF();
		Bitmap bitmap565 = in.copy(Bitmap.Config.RGB_565, true);

		FaceDetector fd = new FaceDetector(in.getWidth(), in.getHeight(), 1);
		FaceDetector.Face[] faces = new FaceDetector.Face[1];
		fd.findFaces(bitmap565, faces);
		

		FaceDetector.Face face = faces[0];
		if (face != null){
			try{
				face.getMidPoint(mid);
				return mid;
			} catch (NullPointerException n){}
		}
		return null;

	}
	
	private static byte[] bitmapToBytes(Bitmap in){
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		in.compress(CompressFormat.PNG, 0, bos);
		return bos.toByteArray();
	}

	
	public static byte[] resize(byte[] picArray, int size, boolean faceDetect){
		if (picArray == null){
			return null;
		}
		Bitmap pic = BitmapFactory.decodeByteArray(picArray, 0, picArray.length);
		if (pic == null){
			return null;
		}
		
		size = Math.min(size, Math.min(pic.getHeight(), pic.getWidth()));
		if (size % 2 != 0)
			size--;
		Log.i("sizes", "old width:"+ pic.getWidth() + " old height:" + pic.getHeight() + " new size:" + size);
		Bitmap scaledPic = scale(pic, size);

		int width = scaledPic.getWidth();
		int height = scaledPic.getHeight();
		
		//if pic is already square, we are done now
		if (width == height){
			return bitmapToBytes(scaledPic);
		}
		
		PointF mid = null;
		int cropcenter;
				
		if (faceDetect)
			mid = findFaceMid(scaledPic);
		
		
		Bitmap out;
		if (width > height){
			if (mid != null)
				cropcenter = Math.max(size/2, Math.min((int) Math.floor(mid.y), width - size/2));
			else
				cropcenter = width/2;
			Log.i("CROPPING", "width:" + width +" center:" + cropcenter + " size:" + size + " left edge:" +  (cropcenter - size/2) + " right edge:" +  (cropcenter + size/2));
			out = Bitmap.createBitmap(scaledPic, cropcenter - size/2, 0, size, size);
		} else {
			if (mid != null)
				cropcenter = Math.max(size/2, Math.min((int) Math.floor(mid.x), height - size/2));
			else
				cropcenter = height/2;
			out = Bitmap.createBitmap(scaledPic, 0, 0, size, size);
		}
		
		return bitmapToBytes(out);
	}

}