Best Image Processing for Higher Face Detection Rate Using Haar Cascades

This chapter finds the best image processing technique that when implemented on a group photo as a preprocessing increases the number of faces detected using the Haar feature-based face detection algorithm. Group photo is a photograph or a picture or an image where we have several faces. Many times not all the faces are detected when a face detection algorithm is implemented on any group photo. So, to detect more number of faces, the image is preprocessed with different preprocessing techniques and each resultant image is examined. Haar feature-based face detection is implemented on each of the resultant images and checked whether any new face(s) has/have been detected or not compared to the faces detected with just the gray image (the one without preprocessing). In fact, the same preprocessing technique is implemented on a set of 15 images and the number of new faces detected in each image is noted. Finally, the total number of new faces detected on the entire set of images is obtained. The same process is repeated with other preprocessing techniques. The preprocessing technique that gives the highest number of new faces is selected as the best image processing technique that a group photo should undergo prior to the implementation of the Haar feature face detection algorithm.