Android 圖像處理

一.圖像處理事例

（1）實驗目的

                    通過三個seekbar調節相片的色相、飽和度、亮度。

（2）步驟。
1.複製bitmap獲取canvas設置抗鋸齒畫筆 因爲是無法直接在原圖上對圖片進行修改的。

         Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bmp);
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

    2.分別設置 色相、飽和度、亮度。

 ColorMatrix hueMatrix = new ColorMatrix();//設置色相 
        hueMatrix.setRotate(0, hue);
        hueMatrix.setRotate(1, hue);
        hueMatrix.setRotate(2, hue);
        // 0 1 2 分別代表紅色綠色藍色

ColorMatrix saturationMatrix = new ColorMatrix();
        saturationMatrix.setSaturation(saturation);

ColorMatrix lumMatrix = new ColorMatrix();
             lumMatrix.setScale(lum, lum, lum, 1);
            //設置亮度

    3.通過ColorMatrix對象的postContat方法封裝

             ColorMatrix imageMatrix = new ColorMatrix();
             imageMatrix.postConcat(hueMatrix);
             imageMatrix.postConcat(saturationMatrix);
             imageMatrix.postConcat(lumMatrix);

paint.setColorFilter(new ColorMatrixColorFilter(imageMatrix));
canvas.drawBitmap(bm, 0, 0, paint);
return bmp;
//繪製原有的bitmap

            4.對seekbar設置監聽和點擊事件

public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        switch (seekBar.getId()) {
            case R.id.seekbarHue:
                mHue = (progress - MID_VALUE) * 1.0F / MID_VALUE * 180;
                break;
            case R.id.seekbarSaturation:
                mStauration = progress * 1.0F / MID_VALUE;
                break;
            case R.id.seekbatLum:
                mLum = progress * 1.0F / MID_VALUE;
                break;
        }
        mImageView.setImageBitmap(ImageHelper.handleImageEffect(bitmap, mHue, mStauration, mLum));
    }