public override bool OnOptionsItemSelected(IMenuItem item) { Log.Info(Tag, "Menu Item selected " + item); if (item == _itemPickPhoto) { var imageIntent = new Intent(); imageIntent.SetType("image/*"); imageIntent.SetAction(Intent.ActionGetContent); StartActivityForResult(Intent.CreateChooser(imageIntent, "Select photo"), 0); } else if (item == _itemGray) { // 灰度图 _gray = new Mat(_raw.Width(), _raw.Height(), CvType.Cv8uc1); Imgproc.CvtColor(_raw, _gray, Imgproc.ColorRgb2gray); ShowImage(_gray); } else if (item == _itemThreshold) { // 二值化 _threshold = new Mat(_image.Width, _image.Height, CvType.Cv8uc1); Imgproc.Threshold(_gray, _threshold, 168, 255, Imgproc.ThreshBinary); ShowImage(_threshold); } else if (item == _itemFindContours) { // 查找最大连通区域 IList <MatOfPoint> contours = new JavaList <MatOfPoint>(); Mat hierarchy = new Mat(); var target = _threshold.Clone(); Imgproc.FindContours(target, contours, hierarchy, Imgproc.RetrExternal, Imgproc.ChainApproxNone); MatOfPoint max = new MatOfPoint(); double contour_area_max = 0; if (contours.Any()) { foreach (var contour in contours) { var contour_area_temp = Math.Abs(Imgproc.ContourArea(contour)); if (contour_area_temp > contour_area_max) { contour_area_max = contour_area_temp; max = contour; } } } var last = new JavaList <MatOfPoint>(); last.Add(max); Imgproc.DrawContours(_raw, last, -1, new Scalar(255, 0, 0)); ShowImage(_raw); } else if (item == _itemCreateTrimap) { // 生成三元图 暂时先用生成的图替代 var imageIntent = new Intent(); imageIntent.SetType("image/*"); imageIntent.SetAction(Intent.ActionGetContent); StartActivityForResult(Intent.CreateChooser(imageIntent, "Select photo"), 1); } else if (item == _itemSharedMatting) { // 扣图 var sharedMatting = new SharedMatting(); sharedMatting.SetImage(_raw); sharedMatting.SetTrimap(_trimap); sharedMatting.SolveAlpha(); } return(base.OnOptionsItemSelected(item)); }