OpenCV的人脸检测功能在一般场合还是不错的。而ubuntu正好提供了python-opencv这个包,用它可以方便地实现人脸检测的代码。
写代码之前应该先安装python-opencv:
$ sudo apt-get install python-opencv
具体原理就不多说了,可以参考一下这篇文章。直接上源代码。
#!/usr/bin/python # -*- coding: UTF-8 -*- # face_detect.py # Face Detection using OpenCV. Based on sample code from: # http://python.pastebin.com/m76db1d6b # Usage: python face_detect.py import sys, os from opencv.cv import * from opencv.highgui import * from PIL import Image, ImageDraw from math import sqrt def detectObjects(image): """Converts an image to grayscale and prints the locations of any faces found""" grayscale = cvCreateImage(cvSize(image.width, image.height), 8, 1) cvCvtColor(image, grayscale, CV_BGR2GRAY) storage = cvCreateMemStorage(0) cvClearMemStorage(storage) cvEqualizeHist(grayscale, grayscale) cascade = cvLoadHaarClassifierCascade( \'/usr/share/opencv/haarcascades/haarcascade_frontalface_default.xml\', cvSize(1,1)) faces = cvHaarDetectObjects(grayscale, cascade, storage, 1.1, 2, CV_HAAR_DO_CANNY_PRUNING, cvSize(20,20)) result = [] for f in faces: result.append((f.x, f.y, f.x+f.width, f.y+f.height)) return result def grayscale(r, g, b): return int(r * .3 + g * .59 + b * .11) def process(infile, outfile): image = cvLoadImage(infile); if image: faces = detectObjects(image) im = Image.open(infile) if faces: draw = ImageDraw.Draw(im) for f in faces: draw.rectangle(f, outline=(255, 0, 255)) im.save(outfile, "JPEG", quality=100) else: print "Error: cannot detect faces on %s" % infile if __name__ == "__main__": process(\'input.jpg\', \'output.jpg\')