android 两张图片覆盖 合成为一张 + 处理（图片合成、图片圆角、图片翻转、图片缩放）

android 两张图片覆盖 合成为一张

infor from - http://devdd.sinaapp.com/post-282.html

把一张图片覆盖到另一种图片上，合并保存为一张图片

思路：创建这两种图片的 bitmap 对象，得到底图的高度和宽度，根据此尺寸创建新的 bitmap 对象，及 canvas 画布，先画入底图，然后再在目标坐标画另一张图片，保存

//创建两个bitmap，一个做为底层，一个做为上层
Bitmap background = BitmapFactory.decodeResource(getResources(), R.drawable.a);
Bitmap front = BitmapFactory.decodeResource(getResources(), R.drawable.t1);

//取得底层的宽高
int bgWidth = background.getWidth();   
int bgHeight = background.getHeight();

//创建新bitmap
Bitmap newbmp = Bitmap.createBitmap(bgWidth, bgHeight, Config.ARGB_8888);  
Canvas cv = new Canvas(newbmp);   
cv.drawBitmap(background, 0, 0, null);//在 0，0坐标开始画入bg   
cv.drawBitmap(front, 0, 0, null);//在 0，0坐标开始画入fg ，可以从任意位置画入
cv.save(Canvas.ALL_SAVE_FLAG);//保存
cv.restore();//存储   

//在图像视图中显示合成后的图片
ImageView img = (ImageView)findViewById(R.id.img);
img.setImageBitmap(newbmp);

//保存到SD卡中
FileOutputStream fos = null;
String filepath = Environment.getExternalStorageDirectory()
  + File.separator + "newimg.png";
FileOutputStream m_fileOutPutStream = null;
try {
  m_fileOutPutStream = new FileOutputStream(filepath);
  newbmp.compress(CompressFormat.PNG, 100, m_fileOutPutStream);
  m_fileOutPutStream.flush();
  m_fileOutPutStream.close();
} catch (Exception e) {
} finally {
    if (fos != null) {
  try {
      fos.flush();
      fos.close();
  } catch (IOException e) {
  }
    }
}

Android之图片处理（图片合成、图片圆角、图片翻转、图片缩放）

infor from - http://www.cnblogs.com/olvo/archive/2012/04/14/2447097.html



图片合成

/**
* 图片合成
* @param bitmap
* @return
*/
private Bitmap createBitmap( Bitmap src, Bitmap watermark ) {
if( src == null ) {
return null;
}
int w = src.getWidth();
int h = src.getHeight();
int ww = watermark.getWidth();
int wh = watermark.getHeight();
//create the new blank bitmap
Bitmap newb = Bitmap.createBitmap( w, h, Config.ARGB_8888 );//创建一个新的和SRC长度宽度一样的位图
Canvas cv = new Canvas( newb );
//draw src into
cv.drawBitmap( src, 0, 0, null );//在 0，0坐标开始画入src
//draw watermark into
cv.drawBitmap( watermark, w - ww + 5, h - wh + 5, null );//在src的右下角画入水印
//save all clip 
cv.save( Canvas.ALL_SAVE_FLAG );//保存
//store
cv.restore();//存储
return newb;
}



图片圆角

/**
* 图片圆角
* @param bitmap
* @return
*/
public static Bitmap getRoundedCornerBitmap(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 = 12;

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;
}



图片缩放、翻转和旋转



/**
* 缩放、翻转和旋转图片
* @param bmpOrg
* @param rotate
* @return
*/
private android.graphics.Bitmap gerZoomRotateBitmap(
android.graphics.Bitmap bmpOrg, int rotate) {
// 获取图片的原始的大小
int width = bmpOrg.getWidth();
int height = bmpOrg.getHeight();

int newWidth = 300;
int newheight = 300;
// 定义缩放的高和宽的比例
float sw = ((float) newWidth) / width;
float sh = ((float) newheight) / height;
// 创建操作图片的用的Matrix对象
android.graphics.Matrix matrix = new android.graphics.Matrix();
// 缩放翻转图片的动作
// sw sh的绝对值为绽放宽高的比例，sw为负数表示X方向翻转，sh为负数表示Y方向翻转
matrix.postScale(sw, sh);
// 旋转30*
matrix.postRotate(rotate);
//创建一个新的图片 
android.graphics.Bitmap resizeBitmap = android.graphics.Bitmap
.createBitmap(bmpOrg, 0, 0, width, height, matrix, true);
return resizeBitmap;
}