cvtColorAsync function
CvtColor converts an image from one color space to another. It converts the src Mat image to the dst Mat using the code param containing the desired ColorConversionCode color space.
For further details, please see: http:///docs.opencv.org/master/d7/d1b/group__imgproc__misc.html#ga4e0972be5de079fed4e3a10e24ef5ef0
Implementation
Future<Mat> cvtColorAsync(Mat src, int code) async =>
cvRunAsync<Mat>((callback) => cimgproc.CvtColor_Async(src.ref, code, callback), matCompleter);