Android - Bitmap操作汇总

た入场券 2022-06-09 10:27 223阅读 0赞

*  Bitmap缩放

/** * 缩放Bitmap * * @param src 原bitmap * @param width 缩放后的宽度 * @param height 缩放后的高度 * @return 缩放后的bitmap */
        public static Bitmap scaleBitmap(Bitmap src, int width, int height) {
            int srcW = src.getWidth();
            int srcH = src.getHeight();
    
            Matrix matrix = new Matrix();
            matrix.setScale(((float) width) / srcW, ((float) height) / srcH);
    
            return Bitmap.createBitmap(src, 0, 0, srcW, srcH, matrix, false);
        }

*  Bitmap裁剪

/** * 将原bitmap裁剪成正方形 * * @param src 原bitmap * @return 正方形的bitmap */
        public static Bitmap centerCropSquare(Bitmap src) {
            int w = src.getWidth();
            int h = src.getHeight();
            System.out.println(w + "," + h);
    
            if (w == h) {
                return src;
            } else if (w > h) {
                return Bitmap.createBitmap(src, (w - h) / 2, 0, h, h);
            } else {
                return Bitmap.createBitmap(src, 0, (h - w) / 2, w, w);
            }
        }

/** * 创建圆形的Bitmap * * @param src 原Bitmap * @return 创建的圆形Bitmap */
        public static Bitmap createRoundBitmap(Bitmap src) {
            if (src == null) return null;
            Bitmap bmp = centerCropSquare(src);//首先裁剪成正方形
            int size = bmp.getWidth();
    
            RectF rectF = new RectF(0, 0, size, size);
    
            Bitmap bg = Bitmap.createBitmap(size, size, bmp.getConfig());
            Canvas canvas = new Canvas(bg);
            Paint paint = new Paint();
            paint.setAntiAlias(true);
            canvas.drawRoundRect(rectF, size / 2, size / 2, paint);
            paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
            canvas.drawBitmap(bmp, 0, 0, paint);
    
            return bg;
        }

*  Bitmap旋转

/** * 旋转Bitmap * 注：该方法会导致Bitmap大小变大 * * @param src 原bitmap * @param degree 旋转角度 * @return 旋转之后的bitmap */
        public static Bitmap rotateBitmap(Bitmap src, int degree) {
            Matrix matrix = new Matrix();
            matrix.postRotate(degree);
            return Bitmap.createBitmap(src, 0, 0, src.getWidth(), src.getHeight(), matrix, false);
        }