I'm working with libsvm and I must perform a multiclass pixel-based classification. I want to classify an image which contains Four classes. For training, I have extracted SURF dense features for each class and out it them in Data_Train.xlsx in which first column is the class and the rest is the SURF features. For test, I have extracted SURF dense features of the image ( that contain four classes at the same time). My question is how to classify each pixel of this image and predict its class using Libsvm and then visualize the results.