How to zoom in and out bitmap instance code in Android

CopyCodeThe Code is as follows:/** bitmap Amplification Method */
Private Static bitmap big (Bitmap bitmap ){
Matrix matrix = new matrix ();
Matrix. postscale (1.5f, 1.5f); // The ratio of length to width to zoom in or out.
Bitmap resizebmp = bitmap. createbitmap (bitmap, 0,0, bitmap. getwidth (), bitmap. getheight (), matrix, true );
Return resizebmp;
}
/** Method for downgrading bitmap */
Private Static bitmap small (Bitmap bitmap ){
Matrix matrix = new matrix ();
Matrix. postscale (0.8f, 0.8f); // The ratio of length to width.
Bitmap resizebmp = bitmap. createbitmap (bitmap, 0,0, bitmap. getwidth (), bitmap. getheight (), matrix, true );
Return resizebmp;
}