ImageHelper.java

package com.tos_bot.utility;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.Canvas;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Matrix;
import android.graphics.Paint;

/**
 * @author frankwang
 *
 */
public  class ImageHelper {

	public ImageHelper(){
	}

	
	static public void savePng(String Path, Bitmap bm) {
		try {
			File file = new File(Path + ".png");
			file.createNewFile();
			BufferedOutputStream out = new BufferedOutputStream(
					new FileOutputStream(file));
			bm.compress(CompressFormat.PNG, 100, out);

			out.flush();
			out.close();
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	static public Bitmap resize(Bitmap bm, int newWidth, int newHeight){
	    int width = bm.getWidth();
	    int height = bm.getHeight();
	    float scaleWidth = ((float) newWidth) / width;
	    float scaleHeight = ((float) newHeight) / height;
	    // CREATE A MATRIX FOR THE MANIPULATION
	    Matrix matrix = new Matrix();
	    // RESIZE THE BIT MAP
	    matrix.postScale(scaleWidth, scaleHeight);

	    // "RECREATE" THE NEW BITMAP
	    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
	    return resizedBitmap;
	}
	
	public static int[] BitmaptoGrayscale(Bitmap bmSrc)
	{     
		/*
		int color[] = new int[6]; // RGBDLH
		int picw = bmpOriginal.getWidth();
		int pich = bmpOriginal.getHeight();
		int[] pix = new int[picw * pich];
		int[] ret = new int[picw * pich];
		bmpOriginal.getPixels(pix, 0, picw, 0, 0, picw, pich);
		int r, g, b;
		for (int i = 0; i < pix.length; i++) {
			int _red = ((pix[i]) >> 16) & 0xFF;
			int _green = ((pix[i]) >> 8) & 0xFF;
			int _blue = ((pix[i])) & 0xFF;
			ret[i]=(int) (0.3 * _red + 0.59 * _green + 0.11 * _blue);

		}
		*/
		int width = bmSrc.getWidth();  
        int height = bmSrc.getHeight();  
        // 创建目标灰度图像  
        Bitmap bmpGray = null;  
        bmpGray = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);  
        // 创建画布  
        Canvas c = new Canvas(bmpGray);  
        Paint paint = new Paint();  
        ColorMatrix cm = new ColorMatrix();  
        cm.setSaturation(0);  
        ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);  
        paint.setColorFilter(f);  
        c.drawBitmap(bmSrc, 0, 0, paint); 
        int[] pix = new int[width * height];
        int i =0;
        for(int h =0;h<height;h++)
        	for(int w=0;w<width;w++){
        		 pix[i] = bmpGray.getPixel(w,h);
        		 i++;
        	}
	    return pix;
	}
	
	public static int average(int[] pixels) {
		float m = 0;
		for (int i = 0; i < pixels.length; ++i) {
			m += pixels[i];
		}
		m = m / pixels.length;
		return (int) m;
	}
	
	public static int rgbToGray(int pixels) {
		// int _alpha = (pixels >> 24) & 0xFF;
		int _red = (pixels >> 16) & 0xFF;
		int _green = (pixels >> 8) & 0xFF;
		int _blue = (pixels) & 0xFF;
		return (int) (0.3 * _red + 0.59 * _green + 0.11 * _blue);
	}
	
	public static char binaryToHex(int binary) {
		char ch = ' ';
		switch (binary)
		{
		case 0:
			ch = '0';
			break;
		case 1:
			ch = '1';
			break;
		case 2:
			ch = '2';
			break;
		case 3:
			ch = '3';
			break;
		case 4:
			ch = '4';
			break;
		case 5:
			ch = '5';
			break;
		case 6:
			ch = '6';
			break;
		case 7:
			ch = '7';
			break;
		case 8:
			ch = '8';
			break;
		case 9:
			ch = '9';
			break;
		case 10:
			ch = 'a';
			break;
		case 11:
			ch = 'b';
			break;
		case 12:
			ch = 'c';
			break;
		case 13:
			ch = 'd';
			break;
		case 14:
			ch = 'e';
			break;
		case 15:
			ch = 'f';
			break;
		default:
			ch = ' ';
		}
		return ch;
	}
}