ImageUtil.java

package com.znv.linkup.core.util;

import java.util.ArrayList;
import java.util.List;

import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;

/**
 * 图片缩放处理类
 * 
 * @author yzb
 * 
 */
public class ImageUtil {

    /**
     * 根据大小缩放图片
     * 
     * @param bitmap
     *            当前图片
     * @param newSizeX
     *            缩放后的宽度
     * @param newSizeY
     *            缩放后的高度
     * @return 缩放后的图片
     */
    public static Bitmap scaleBitmap(Bitmap bitmap, int newSizeX, int newSizeY) {
        float scaleX = (float) (newSizeX * 1.0 / bitmap.getWidth());
        float scaleY = (float) (newSizeY * 1.0 / bitmap.getHeight());
        return scaleBitmap(bitmap, scaleX, scaleY);
    }

    /**
     * 根据比例缩放图片
     * 
     * @param bitmap
     *            当前图片
     * @param scaleX
     *            宽度缩放比例
     * @param scaleY
     *            高度缩放比例
     * @return 缩放后的图片
     */
    public static Bitmap scaleBitmap(Bitmap bitmap, float scaleX, float scaleY) {
        Matrix matrix = new Matrix();
        matrix.postScale(scaleX, scaleY);
        return Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
    }

    /**
     * 将图片转化为圆形图片
     * 
     * @param bitmap
     *            原图
     * @return 圆形图
     */
    public static Bitmap roundBitmap(Bitmap bitmap) {
        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 = bitmap.getWidth() / 2;

        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;
    }

    /**
     * 分割bitmap
     * 
     * @param bm
     *            源图片
     * @param xcount
     *            水平个数
     * @param ycount
     *            垂直个数
     * @return 小图片数组
     */
    public static List<Bitmap> cutImage(Bitmap bm, int xcount, int ycount) {
        if (bm == null) {
            return null;
        }
        int width = bm.getWidth();
        int height = bm.getHeight();
        int imageWidth = width / xcount;
        int imageHeight = height / ycount;
        List<Bitmap> images = new ArrayList<Bitmap>(xcount * ycount);
        for (int i = 0; i < xcount; i++) {
            for (int j = 0; j < ycount; j++) {
                try {
                    images.add(Bitmap.createBitmap(bm, i * imageWidth, j * imageHeight, imageWidth, imageHeight));
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        }
        return images;
    }
}