图像质量的android

Question

我需要解决按位图大小抛出的OutOfMemory错误。

我使用了这段代码：

public static Bitmap decodeSampledBitmapFromSDcard(String file,
            int reqWidth, int reqHeight) {

        // First decode with inJustDecodeBounds=true to check dimensions
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(file, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, reqWidth,
                reqHeight);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeFile(file, options);
    }

    public static int calculateInSampleSize(BitmapFactory.Options options,
            int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            if (width > height) {
                inSampleSize = Math.round((float) height / (float) reqHeight);
            } else {
                inSampleSize = Math.round((float) width / (float) reqWidth);
            }
        }
        return inSampleSize;
    }

但图像质量很差。

我需要另一种方法来调整图像大小以使其位图对象小而不会破坏质量。

Answer 1

int newWidth = 640;
int newHeight = 480;
loat scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
Matrix matrix = new Matrix();
                                        matrix.postScale(scaleWidth, scaleHeight);

Bitmap nResizedBitmap = Bitmap.createBitmap(b, 0, 0, width, height, matrix,true);
                                                                                FileOutputStream out = new FileOutputStream(...outfile...);                                         nResizedBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);