My application slows down when processing Kinect RGB images with EMGU library

Question

I'm currently using Kinect SDK with C# ( WPF application). I need to get RGB stream and process the images with EMGU library. The problem is when i try to process the image with EMGU ( like converting image's format and change the colour of some pixels ) the application slows down and takes too long to respond . I'm using 8GO RAM / Intel HD graphics 4000 / Intel core i7 .

Here's my simple code : http://pastebin.com/5frLRwMN

Please help me :'(

Answer 1

I have run considerably heavier code (blob analysis) with the Kinect on a per frame basis and got away with great performance on a machine of similar configuration as yours, so I believe we can rule out your machine as the problem. I don't see any EMGU code in your sample however. In your example, you loop through 307k pixels with a pair of for loops. This is naturally a costly procedure to run, depending on the code in your loops. As you might expect, GetPixel and SetPixel are very slow methods to execute.

To speed up your code, first turn your image into an Emgu Image. Then to access your image, use a Byte:

Byte workImageRed = image.Data[x, y, 0];
Byte workImageGreen = image.Data[x, y, 1];
...

The third column refers to the BGR data. To set the pixel to another colour, try something like this:

byte[,,] workIm = image.Data;
workIm[x, y, 0] = 255;
workIm[x, y, 1] = 20;
...

Alternatively, you can set the pixel to a colour directly:

image[x, y] = new Bgr(Color.Blue);

This might be slower however.

Answer 2

Image processing is always slow. And if you do it at 30fps, it's normal that you get you app to hang: real time image processing is always a challenge. You may need to drop some frames in order to increase performace (...or perhaps switch to native C++ and seek a faster library).