Android 图片Bitmap的剪切

http://blog.csdn.net/stoppig/article/details/23202129

版权声明：本文为博主原创文章，未经博主允许不得转载。

目录(?)[+]

一、什么是Android中的Bitmap

Bitmap是Android系统中的图像处理的最重要类之一。用它可以获取图像文件信息，进行图像剪切、旋转、缩放等操作，并可以指定格式保存图像文件。

二、Bitmap的剪切基本操作

public static Bitmap createBitmap (Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter)
从原始位图剪切图像，这是一种高级的方式。可以用Matrix(矩阵)来实现旋转等高级方式截图
参数说明：
　　Bitmap source：要从中截图的原始位图
　　int x:起始x坐标
　　int y：起始y坐标
int width：要截的图的宽度
int height：要截的图的宽度
Bitmap.Config  config：一个枚举类型的配置，可以定义截到的新位图的质量
返回值：返回一个剪切好的Bitmap

三、Bitmap剪切的封装

实际使用中，因为项目需要时常需要对基本功能进行封装，下面是一段封装的代码，仅供参考。

 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;

 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Bitmap.Config;
 import android.graphics.BitmapFactory;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuff.Mode;
 import android.graphics.PorterDuffXfermode;
 import android.graphics.Rect;
 import android.graphics.RectF;


 public class BitmapCut
 {

     /**
      * 通过资源id转化成Bitmap
      *
      * @param context
      * @param resId
      * @return
      */
     public static Bitmap ReadBitmapById(Context context, int resId)
     {
         BitmapFactory.Options opt = new BitmapFactory.Options();
         opt.inPreferredConfig = Bitmap.Config.RGB_565;
         opt.inPurgeable = true;
         opt.inInputShareable = true;

         InputStream is = context.getResources().openRawResource(resId);
         return BitmapFactory.decodeStream(is, null, opt);
     }



     /**
      * 设置背景为圆角
      *
      * @param bitmap
      * @param pixels
      * @return
      */
     public static Bitmap removeYuanjiao(Bitmap bitmap, int pixels)
     {
         int width = bitmap.getWidth();
         int height = bitmap.getHeight();

         Bitmap creBitmap = Bitmap.createBitmap(width, height,
                 android.graphics.Bitmap.Config.ARGB_8888);
         Canvas canvas = new Canvas(creBitmap);

         Paint paint = new Paint();
         float roundPx = pixels;
         RectF rectF = new RectF(0, 0, bitmap.getWidth() - pixels,
                 bitmap.getHeight() - pixels);
         paint.setAntiAlias(true);

         canvas.drawARGB(0, 0, 0, 0);
         canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
         paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));

         canvas.drawBitmap(bitmap, 0, 0, paint);
         if (!bitmap.isRecycled())
             bitmap.recycle();

         return creBitmap;
     }

     /**
      * 按正方形裁切图片
      */
     public static Bitmap ImageCrop(Bitmap bitmap, boolean isRecycled)
     {

         if (bitmap == null)
         {
             return null;
         }

         int w = bitmap.getWidth(); // 得到图片的宽，高
         int h = bitmap.getHeight();

         int wh = w > h ? h : w;// 裁切后所取的正方形区域边长

         int retX = w > h ? (w - h) / 2 : 0;// 基于原图，取正方形左上角x坐标
         int retY = w > h ? 0 : (h - w) / 2;

         Bitmap bmp = Bitmap.createBitmap(bitmap, retX, retY, wh, wh, null,
                 false);
         if (isRecycled && bitmap != null && !bitmap.equals(bmp)
                 && !bitmap.isRecycled())
         {
             bitmap.recycle();
             bitmap = null;
         }

         // 下面这句是关键
         return bmp;// Bitmap.createBitmap(bitmap, retX, retY, wh, wh, null,
                     // false);
     }

     /**
      * 按长方形裁切图片
      *
      * @param bitmap
      * @return
      */
     public static Bitmap ImageCropWithRect(Bitmap bitmap)
     {
         if (bitmap == null)
         {
             return null;
         }

         int w = bitmap.getWidth(); // 得到图片的宽，高
         int h = bitmap.getHeight();

         int nw, nh, retX, retY;
         if (w > h)
         {
             nw = h / 2;
             nh = h;
             retX = (w - nw) / 2;
             retY = 0;
         } else
         {
             nw = w / 2;
             nh = w;
             retX = w / 4;
             retY = (h - w) / 2;
         }

         // 下面这句是关键
         Bitmap bmp = Bitmap.createBitmap(bitmap, retX, retY, nw, nh, null,
                 false);
         if (bitmap != null && !bitmap.equals(bmp) && !bitmap.isRecycled())
         {
             bitmap.recycle();
             bitmap = null;
         }
         return bmp;// Bitmap.createBitmap(bitmap, retX, retY, nw, nh, null,
                     // false);
     }

     /**
      * Bitmap --> byte[]
      *
      * @param bmp
      * @return
      */
     public static byte[] readBitmap(Bitmap bmp)
     {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         bmp.compress(Bitmap.CompressFormat.JPEG, 60, baos);
         try
         {
             baos.flush();
             baos.close();
         } catch (IOException e)
         {
             e.printStackTrace();
         }
         return baos.toByteArray();
     }


     /**
      * 将图像裁剪成圆形
      *
      * @param bitmap
      * @return
      */
     public static Bitmap toRoundBitmap(Bitmap bitmap)
     {
         if (bitmap == null)
         {
             return null;
         }

         int width = bitmap.getWidth();
         int height = bitmap.getHeight();
         float roundPx;
         float left, top, right, bottom, dst_left, dst_top, dst_right, dst_bottom;
         if (width <= height)
         {
             roundPx = width / 2;
             top = 0;
             bottom = width;
             left = 0;
             right = width;
             height = width;
             dst_left = 0;
             dst_top = 0;
             dst_right = width;
             dst_bottom = width;
         } else
         {
             roundPx = height / 2;
             float clip = (width - height) / 2;
             left = clip;
             right = width - clip;
             top = 0;
             bottom = height;
             width = height;
             dst_left = 0;
             dst_top = 0;
             dst_right = height;
             dst_bottom = height;
         }

         Bitmap output = Bitmap.createBitmap(width, height, Config.ARGB_8888);
         Canvas canvas = new Canvas(output);

         final int color = 0xff424242;
         final Paint paint = new Paint();
         final Rect src = new Rect((int) left, (int) top, (int) right,
                 (int) bottom);
         final Rect dst = new Rect((int) dst_left, (int) dst_top,
                 (int) dst_right, (int) dst_bottom);
         final RectF rectF = new RectF(dst);

         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, src, dst, paint);
         if (bitmap != null && !bitmap.isRecycled())
         {
             bitmap.recycle();
             bitmap = null;
         }
         return output;
     }

     // 将图片变成带圆边的圆形图片
     public static Bitmap getRoundBitmap(Bitmap bitmap, int width, int height)
     {
         if (bitmap == null)
         {
             return null;
         }
         // 将图片变成圆角
         Bitmap roundBitmap = Bitmap.createBitmap(width, height,
                 Config.ARGB_8888);
         Canvas canvas = new Canvas(roundBitmap);
         Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         int len = (width > height) ? height : width;
         canvas.drawCircle(width / 2, height / 2, len / 2 - 8, paint);
         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
         Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, len, len, true);
         canvas.drawBitmap(scaledBitmap, 0, 0, paint);
         // 将图片加圆边
         Bitmap outBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
         canvas = new Canvas(outBitmap);
         paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         paint.setColor(0xffffffff);
         canvas.drawCircle(width / 2, height / 2, len / 2 - 4, paint);
         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_OVER));
         canvas.drawBitmap(roundBitmap, 0, 0, paint);
         bitmap.recycle();
         bitmap = null;
         roundBitmap.recycle();
         roundBitmap = null;
         scaledBitmap.recycle();
         scaledBitmap = null;
         return outBitmap;
     }

     // 将图片变成带圆边的圆形图片
     public static Bitmap getRoundBitmap(Bitmap bitmap, int width, int height,
             int color)
     {
         if (bitmap == null)
         {
             return null;
         }
         // 将图片变成圆角
         Bitmap roundBitmap = Bitmap.createBitmap(width, height,
                 Config.ARGB_8888);
         Canvas canvas = new Canvas(roundBitmap);
         Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         int len = (width > height) ? height : width;
         canvas.drawCircle(width / 2, height / 2, len / 2 - 8, paint);
         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
         Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmap, len, len, true);
         canvas.drawBitmap(scaledBitmap, 0, 0, paint);
         // 将图片加圆边
         Bitmap outBitmap = Bitmap.createBitmap(width, height, Config.ARGB_8888);
         canvas = new Canvas(outBitmap);
         paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         paint.setColor(color);
         canvas.drawCircle(width / 2, height / 2, len / 2 - 4, paint);
         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_OVER));
         canvas.drawBitmap(roundBitmap, 0, 0, paint);
         bitmap.recycle();
         bitmap = null;
         roundBitmap.recycle();
         roundBitmap = null;
         scaledBitmap.recycle();
         scaledBitmap = null;
         return outBitmap;
     }

     /**
      * function:图片转圆角
      *
      * @param bitmap
      *            需要转的bitmap
      * @param pixels
      *            转圆角的弧度
      * @return 转圆角的bitmap
      */
     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);
         if (bitmap != null && !bitmap.isRecycled())
         {
             bitmap.recycle();
         }
         return output;
     }

     /**
      * 获取指定的圆角图片
      *
      * @param bitmap
      * @return
      */
     public static Bitmap getRadiusBitmap(Bitmap bitmap)
     {
         Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
         paint.setColor(0xffffffff);
         Bitmap radiusBitmap = Bitmap.createBitmap(bitmap.getWidth(),
                 bitmap.getHeight(), Config.ARGB_8888);
         Canvas canvas = new Canvas(radiusBitmap);
         RectF rectF = new RectF(0, 0, bitmap.getWidth(), bitmap.getHeight());
         canvas.drawRoundRect(rectF, 7, 7, paint);
         paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
         canvas.drawBitmap(bitmap, 0, 0, paint);
         if (bitmap != null && !bitmap.isRecycled())
         {
             bitmap.recycle();
         }
         return radiusBitmap;
     }

     // 获得指定大小的圆边的bitmap数组
     public static ArrayList getRadiusBitmapList(String[] pathArray,
             int size, int len, float radius, int color)
     {
         Bitmap canvasBitmap = null;
         Canvas canvas = null;
         Paint paint = null;
         RectF rectF = new RectF(0, 0, len - radius, len - radius);
         File file = null;
         FileInputStream fis = null;
         Bitmap bitmap = null;
         Bitmap scaledBitmap = null;

         ArrayList list = new ArrayList();
         for (int i = 0; i < pathArray.length; i++)
         {
             file = new File(pathArray[i]);
             if (!file.exists())
                 continue;
             try
             {
                 fis = new FileInputStream(file);
                 bitmap = BitmapFactory.decodeStream(fis);
                 if (bitmap != null)
                 {
                     canvasBitmap = Bitmap.createBitmap(len, len,
                             Config.ARGB_8888);
                     canvas = new Canvas(canvasBitmap);
                     paint = new Paint(Paint.ANTI_ALIAS_FLAG);
                     paint.setColor(color);
                     canvas.drawRoundRect(rectF, radius, radius, paint);
                     paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

                     scaledBitmap = Bitmap.createScaledBitmap(bitmap, len, len,
                             true);
                     canvas.drawBitmap(scaledBitmap, 0, 0, paint);
                     list.add(canvasBitmap);
                 }
             } catch (FileNotFoundException e)
             {
             } finally
             {
                 if (fis != null)
                 {
                     try
                     {
                         fis.close();
                     } catch (IOException e1)
                     {
                     }
                 }
             }
             if (list.size() == size)
                 break;
         }
         if (scaledBitmap != null && !scaledBitmap.isRecycled())
         {
             scaledBitmap.recycle();
             scaledBitmap = null;
         }
         if (bitmap != null && !bitmap.isRecycled())
         {
             bitmap.recycle();
             bitmap = null;
         }
         return list;
     }





     /**
      * 按照一定的宽高比例裁剪图片
      *
      * @param bitmap
      * @param num1
      *            长边的比例
      * @param num2
      *            短边的比例
      * @return
      */
     public static Bitmap ImageCrop(Bitmap bitmap, int num1, int num2,
             boolean isRecycled)
     {
         if (bitmap == null)
         {
             return null;
         }
         int w = bitmap.getWidth(); // 得到图片的宽，高
         int h = bitmap.getHeight();
         int retX, retY;
         int nw, nh;
         if (w > h)
         {
             if (h > w * num2 / num1)
             {
                 nw = w;
                 nh = w * num2 / num1;
                 retX = 0;
                 retY = (h - nh) / 2;
             } else
             {
                 nw = h * num1 / num2;
                 nh = h;
                 retX = (w - nw) / 2;
                 retY = 0;
             }
         } else
         {
             if (w > h * num2 / num1)
             {
                 nh = h;
                 nw = h * num2 / num1;
                 retY = 0;
                 retX = (w - nw) / 2;
             } else
             {
                 nh = w * num1 / num2;
                 nw = w;
                 retY = (h - nh) / 2;
                 retX = 0;
             }
         }
         Bitmap bmp = Bitmap.createBitmap(bitmap, retX, retY, nw, nh, null,
                 false);
         if (isRecycled && bitmap != null && !bitmap.equals(bmp)
                 && !bitmap.isRecycled())
         {
             bitmap.recycle();
             bitmap = null;
         }
         return bmp;// Bitmap.createBitmap(bitmap, retX, retY, nw, nh, null,
                     // false);
     }
 }

示例代码：http://download.csdn.net/detail/stop_pig/7162695

顶

0

踩

0

 

 

• 上一篇Android中图片Bitmap的缩放
• 下一篇android 图片Bitmap的旋转
•