OpenCV: Fetch color, intensity and texture of an image
I'm new to OpenCV and just started sifting through the APIs. I intend to fetch the color, intensity and texture values of each pixel constituting the image. I was fiddling with the structure - IplImage to start with but couldn't make much progress.
Please let m开发者_运维技巧e know of any means to do this.
cheers
Have you tried OpenCV 2.0? They have a new C++ interface which makes things much easier. You can use their new Mat class to load images, access pixels efficiently, etc. It's much cleaner than IplImage fun. I use \doc\opencv.pdf as my reference to anything I need. It's got tutorials, and examples with the new C++ interface, etc. - enough and more to get you started.
If you have anymore specific OpenCV questions, please feel free to ask.
Here's some demo code to get you started: (I've used the cv namespace):
// Load the image (looks like MATLAB :) ? )
Mat M = imread("h:\\lena.bmp");
// Display
namedWindow("Lena",CV_WINDOW_AUTOSIZE);
imshow("Lena",M);
waitKey();
// Crop out rectangle from (100,100) of size (200,200) of the red channel
const int offset[2] = {100,100};
const int dims[2] = {200,200};
Mat Red(dims[0],dims[1],CV_8UC1);
// Read it from M into Red
uchar* lena = M.data;
for(int i=0;i<dims[0];++i)
for(int j=0;j<dims[0];++j)
{
// P = i*rows*channels + j*channels + c
Red.at<uchar>(i,j) = *(lena + (i+offset[0])*M.rows*M.channels() + (j+offset[1])*M.channels()+0);
}
//Display
namedWindow("RedRect",CV_WINDOW_AUTOSIZE);
imshow("RedRect",Red);
waitKey();
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