Question

我有应用程序捕获图像并使用重叠图像保存它。放置在捕获图像上方的图像就像是中心有透明部分的边框。问题是在某些设备上图片被破坏并且看起来像这样

所以棕色边框没问题，但拍摄的图像不合适。具体来说，它在HTC sense 3.6（Android 4.0.3）上再现起初我捕获图像并创建带边框的位图。比我把它保存在SD卡上并在下一个活动中显示它。这是我的代码：

private class CameraPictureCallback implements Camera.PictureCallback {

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {

        File pictureFile = PictureStorage.getOutputMediaFile(PictureStorage.MEDIA_TYPE_IMAGE);
        if (pictureFile == null) {
            Logger.getInstance().log("Error creating media file, check storage permissions: ");
            return;
        }

        if (data != null) {

            Bitmap border = BitmapFactory.decodeResource(getResources(), R.drawable.photo_frame);

            BitmapFactory.Options opts = new BitmapFactory.Options();
            opts.inSampleSize = 4;
            Bitmap origin_bitmap = BitmapFactory.decodeByteArray(data, 0, data.length, opts);

            Matrix matrix = new Matrix();
            matrix.postRotate(mRotation);

            //Border is 640x640px
            Bitmap bitmap = Bitmap.createScaledBitmap(origin_bitmap, border.getWidth(), border.getHeight(), false);
            bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

            Bitmap resultBitmap = Bitmap.createBitmap(border.getWidth(), border.getHeight(), Bitmap.Config.ARGB_8888);

            Canvas s = new Canvas(resultBitmap);
            s.drawBitmap(bitmap, 0f, 0f, null);
            s.drawBitmap(border, 0f, 0f, null);

            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                if (resultBitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos)) {
                    fos.close();
                }
                resultBitmap.recycle();
                bitmap.recycle();
                border.recycle();
                origin_bitmap.recycle();

                Intent i = new Intent(getContext(), PictureConfirmActivity.class);
                i.putExtra("filename", pictureFile.getPath());
                getContext().startActivity(i);
            } catch (FileNotFoundException e) {
                Logger.getInstance().log(e);
            } catch (IOException e) {
                Logger.getInstance().log(e);
            }
        }
    }
}

它不会在我的任何设备上重现，但问题非常实际，我需要解决它。我可以想象它可以在这里，resultBitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos)，但它只是一个想法

Answer 1

问题在于设置正确的预览尺寸。我选择了第一个可用的屏幕尺寸，导致这种不可预测的结果。所以正确的解决方案是找到合适的预览尺寸

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    //some code before...
    Camera.Parameters parameters = mCamera.getParameters();
    Camera.Size previewSize = getBestPreviewSize(w, h, parameters);
    parameters.setPreviewSize(previewSize.width, previewSize.height);
    mCamera.setParameters(parameters);
}

private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) {
    Camera.Size result = null;
    for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
        if (size.width <= width && size.height <= height) {
            if (result == null) {
                result = size;
            }
            else {
                int resultArea = result.width * result.height;
                int newArea = size.width * size.height;

                if (newArea > resultArea) {
                    result = size;
                }
            }
        }
    }

    if (result == null) {
        result = parameters.getSupportedPreviewSizes().get(0);
    }

    return result;
}

某些设备上的相机图片保存不正确

1 个答案: