What is machine Learning???
Machine learning is a technique, which is used to do certain works by the computer without human help. Normally, the machine will learn everything from the inputs, and produces a output. If the output is wrong for a certain input data, then the algorithm learns itself, so the next time the output will be correct, for the input. In machine learning, we develop a model, that is trained by using some algorithms, such as SVM, Linear Regression, Logistic regression. After training this model, this can be used in anywhere, to predict the output.
Suppose, to check whether the image contains a face or not. For humans, it is easy to find whether the image contains a face or not. But for computer????. Here we use some machine learning algorithms to create a models, which will be able to identify whether the image contains a face or not. So the next question is how the computer knowns , a face in a image??? . The computer knowns a image contains a face , only by a trained model. So how the model is trained???.. The model is trained from both positive and negative images. We need to have lakhs of images which contains the faces, and another lakhs of image , which does not contains the images. Then we have to use a classification Machine Learning Algorithm to classify , the face.
HOG is the most accurate machine learning algorithm which can be used to train a model, to identify images. We can also use various other method, but for more accuracy and less CPU , we can use HOG to get better results.
