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/**
* @param bitmap 原图
* @param edgeLength 希望得到的正方形部分的边长
* @return 缩放截取正中部分后的位图。
*/
public static Bitmap centerSquareScaleBitmap(Bitmap bitmap, int edgeLength)
{
if(null == bitmap || edgeLength <= 0)
{
return null;
}
Bitmap result = bitmap;
int widthOrg = bitmap.getWidth();
int heightOrg = bitmap.getHeight();
if(widthOrg > edgeLength && heightOrg > edgeLength)
{
//压缩到一个最小长度是edgeLength的bitmap
int longerEdge = (int)(edgeLength * Math.max(widthOrg, heightOrg) / Math.min(widthOrg, heightOrg));
int scaledWidth = widthOrg > heightOrg ? longerEdge : edgeLength;
int scaledHeight = widthOrg > heightOrg ? edgeLength : longerEdge;
Bitmap scaledBitmap;
try{
scaledBitmap = Bitmap.createScaledBitmap(bitmap, scaledWidth, scaledHeight, true);
}
catch(Exception e){
return null;
}
//从图中截取正中间的正方形部分。
int xTopLeft = (scaledWidth - edgeLength) / 2;
int yTopLeft = (scaledHeight - edgeLength) / 2;
try{
result = Bitmap.createBitmap(scaledBitmap, xTopLeft, yTopLeft, edgeLength, edgeLength);
scaledBitmap.recycle();
}
catch(Exception e){
return null;
}
}
return result;
}
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