EmguCV：创建图像直方图-错误

Question

I just switched from OpenCV to EmguCV because C++ applications can't be directly hosted on my target cloud platform -- now my Histogram code won't work after making the necessary changes for the conversion.

Here is a snippet of what I have done:

Image<Gray, Byte> img_gray = new Image<Gray, byte>(frame1_hist.Rows, frame1_hist.Cols);
frame1_hist.CopyTo(img_gray, null);
DenseHistogram hist = new DenseHistogram(256, new RangeF(0, 256));
hist.Calculate(new Image<Gray, Byte>[] { img_gray }, true, null);

An unhandled exception of type 'System.NullReferenceException' occurred in Emgu.CV.dll

I will appreciate your kind help if you may tell me how I can fix this. Also, how can I read the processed image from "hist" after the operation. I am using EmguCv 3.0.0. Thanks

Answer 1

Image<Gray, Byte> img_gray = new Image<Gray, Byte(frame1_hist.Image.Bitmap);
DenseHistogram hist = new DenseHistogram(256, new RangeF(0.0f, 255.0f));

// Histogram Computing

hist.Calculate<Byte>(new Image<Gray, byte>[] { img_gray }, true, null);