裁剪图像的特定部分

Question

我正在构建一个Windows Phone 8相机应用程序。拍完照片后，我想让用户选择裁剪图像的特定部分。就像图像中有一些特定的对象一样，当选择裁剪选项时，它应该突出显示或勾勒出图像的特定部分，并且它应该能够裁剪它，而不是手动裁剪它。

任何具体的方法吗？。

提前致谢。

Answer 1

一种方法是创建WriteableBitmap并将TranslateTransform原始图片放入WritableBitmap。像::

之类的东西

Image workImage = new Image { Source = originalImage, Width = originalWidth, Height = originalHeight };

WriteableBitmap writeableBitmap = new WriteableBitmap(newWidth, newHeight);
writeableBitmap.Render(temporaryImage, new TranslateTransform { X = (originalWidth – newWidth) / -2, Y = (originalHeight – newHEight) / -2 });
writeableBitmap.Invalidate();

//... or some other stream
Stream newImageStream = new MemoryStream();
//set whatever quality settings you like if 75 is no good
writeableBitmap.SaveJpeg(newImageStream, newWidth, newHeight, 0, 75);

// TODO: do something with newImageStream