android图片工具类

package com.mm.mmcalendar.utils;

import java.io.ByteArrayOutputStream;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.PorterDuff;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.os.Environment;

/** 
 *  
 * 
 */
public class Tools {
	/**
	 * 检查是否存在SDCard
	 * 
	 * @return
	 */
	public static boolean hasSdcard() {
		String state = Environment.getExternalStorageState();
		if (state.equals(Environment.MEDIA_MOUNTED)) {
			return true;
		} else {
			return false;
		}
	}

	/**
	 * 把图片变成圆角
	 * 
	 * @param bitmap
	 *            需要修改的图片
	 * @param pixels
	 *            圆角的弧度
	 * @return 圆角图片
	 */
	public static Bitmap toRoundCorner(Bitmap bitmap, int pixels) {

		Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
				bitmap.getHeight(), Config.ARGB_8888);
		Canvas canvas = new Canvas(output);

		final int color = 0xff424242;
		final Paint paint = new Paint();
		final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
		final RectF rectF = new RectF(rect);
		final float roundPx = pixels;

		paint.setAntiAlias(true);
		canvas.drawARGB(0, 0, 0, 0);
		paint.setColor(color);
		canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

		paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
		canvas.drawBitmap(bitmap, rect, rect, paint);

		return output;
	}

	public static Bitmap Bytes2Bimap(byte[] b) {
		if (b.length != 0) {
			return BitmapFactory.decodeByteArray(b, 0, b.length);
		} else {
			return null;
		}
	}

	public static byte[] Bitmap2Bytes(Bitmap bm) {
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
		return baos.toByteArray();
	}

	public static Bitmap drawableToBitmap(Drawable drawable) {

		Bitmap bitmap = Bitmap
				.createBitmap(
						drawable.getIntrinsicWidth(),
						drawable.getIntrinsicHeight(),
						drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
								: Bitmap.Config.RGB_565);
		Canvas canvas = new Canvas(bitmap);
		// canvas.setBitmap(bitmap);
		drawable.setBounds(0, 0, drawable.getIntrinsicWidth(),
				drawable.getIntrinsicHeight());
		drawable.draw(canvas);
		return bitmap;
	}
	
	public static byte[] getImageContentInSize(String pathName, int boundsWidth, int boundsHeight) {
		Bitmap bitmap = BitmapFactory.decodeFile(pathName);

		int srcWidth = bitmap.getWidth();
		int srcHeight = bitmap.getHeight();
		if (srcWidth > boundsWidth || srcHeight > boundsHeight) {

			double boundsRatio = 1.0 * boundsWidth / boundsHeight;
			double srcRatio = 1.0 * srcWidth / srcHeight;
			double scaleRatio;
			if (boundsRatio > srcRatio) {
				scaleRatio = 1.0 * boundsHeight / srcHeight;
			}
			else {
				scaleRatio = 1.0 * boundsWidth / srcWidth;
			}
			int scaleWidth = (int) (srcWidth * scaleRatio);
			int scaleHeight = (int) (srcHeight * scaleRatio);

			bitmap = Bitmap.createScaledBitmap(bitmap, scaleWidth, scaleHeight, false);
		}
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos);
		return bos.toByteArray();
	}
	
	public static Bitmap getRoundedCornerBitmap(Bitmap bitmap, int pixels) {
		Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap
			.getHeight(), Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(output);

		final int color = 0xff424242;
		final Paint paint = new Paint();
		final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
		final RectF rectF = new RectF(rect);
		final float roundPx = pixels;

		paint.setAntiAlias(true);
		canvas.drawARGB(0, 0, 0, 0);
		paint.setColor(color);
		canvas.drawRoundRect(rectF, roundPx, roundPx, paint);

		paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
		canvas.drawBitmap(bitmap, rect, rect, paint);

		return output;
	}
}