android - 位图大小超出 VM 预算

Question

我已经阅读了关于这个问题的那些帖子，但我的情况有点不同，因为我没有显示位图，而是只是对原始数据的图像进行后处理。首先，我调用 ImageProcessing.rgbToBitmap(data,width, height);，它将返回一个 Bitmap 对象。然后我分别执行这 3 个功能。

1. 旋转位图
2. 为位图添加水印叠加层
3. 在位图的右下角添加日期

调用的所有 3 个方法都将创建一个返回位图对象，这可能会导致崩溃，因为我试图每 1000 毫秒保存一次图像!有时保存的图像可能由于内存错误而失真。

我在下面发布我的代码，非常感谢任何建议。不过，我不想在所拍摄图像的质量上妥协。 (需要保留分辨率)

public static Bitmap addWatermark(Resources res, Bitmap source) {
        int w, h;
        Canvas c;
        Paint paint;
        Bitmap bmp, watermark;

        Matrix matrix;
        float scale;
        RectF r;

        w = source.getWidth();
        h = source.getHeight();

        // Create the new bitmap
        bmp = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);

        paint = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.DITHER_FLAG
                | Paint.FILTER_BITMAP_FLAG);

        // Copy the original bitmap into the new one
        c = new Canvas(bmp);
        c.drawBitmap(source, 0, 0, paint);

        // Load the watermark
        watermark = BitmapFactory.decodeResource(res, R.drawable.watermark);
        // Scale the watermark to be approximately 10% of the source image
        // height
        scale = (float) (((float) h * 0.80) / (float) watermark.getHeight());

        // Create the matrix
        matrix = new Matrix();
        matrix.postScale(scale, scale);
        // Determine the post-scaled size of the watermark
        r = new RectF(0, 0, watermark.getWidth(), watermark.getHeight());
        matrix.mapRect(r);
        // Center watermark
        matrix.postTranslate((w - r.width()) / 2, (h - r.height()) / 2);

        // Draw the watermark
        c.drawBitmap(watermark, matrix, paint);
        // Free up the bitmap memory
        watermark.recycle();

        return bmp;
    }

public static Bitmap addDate(Bitmap src, String date) {
        int w = src.getWidth();
        int h = src.getHeight();
        //Bitmap result = Bitmap.createBitmap(w, h, src.getConfig());
        Bitmap result = src;
        Canvas canvas = new Canvas(result);
        canvas.drawBitmap(src, 0, 0, null);

        Paint paint = new Paint(); 
        paint.setColor(Color.rgb(255, 185, 15)); 
        paint.setTextSize(20);
        paint.setAntiAlias(true);
        canvas.drawText(date, w - 200, h - 20, paint);

        return result;
    }
public static Bitmap rotate(Bitmap src, int rotation) {

        int width = src.getWidth();
        int height = src.getHeight();

        // create a matrix for the manipulation
        Matrix matrix = new Matrix();
        // rotate the Bitmap
        matrix.postRotate(rotation);

        // recreate the new Bitmap, swap width and height and apply
        // transform
        Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
                matrix, true);
        return rotatedBitmap;

    }

Answer 1

先试试这个:变化

// Copy the original bitmap into the new one
c = new Canvas(bmp);
c.drawBitmap(source, 0, 0, paint);

与

// Copy the original bitmap into the new one
c = new Canvas(bmp);
bmp.recycle(); //here or below
c.drawBitmap(source, 0, 0, paint);
//below bmp.recycle();

这里:

canvas.drawText(date, w - 200, h - 20, paint);

return result;

与

canvas.drawText(date, w - 200, h - 20, paint);
result.recycle();
return result;

这里

Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
                matrix, true);
return rotatedBitmap;

与

Bitmap rotatedBitmap = Bitmap.createBitmap(src, 0, 0, width, height,
                matrix, true);
return rotatedBitmap;
rotatedBitmap.recycle();

添加所有这些(recycle();)也许这已经足够了，还可以尝试使用较小位图的代码，看看它是否仍然崩溃(比如 50px x 50px)。

不，他们无法增加手机的 VM。