Selective Search for Object Detection 

OpenCV實現目標檢測方法，具體參考論文及官方說明：

https://www.learnopencv.com/selective-search-for-object-detection-cpp-python/

論文參考：Efficient Graph-Based Image Segmentation

#!/usr/bin/env python
'''
Usage:
    ./ssearch.py input_image (f|q)
    f=fast, q=quality
Use "l" to display less rects, 'm' to display more rects, "q" to quit.
'''

import sys
import cv2

if __name__ == '__main__':
    # If image path and f/q is not passed as command
    # line arguments, quit and display help message
    if len(sys.argv) < 3:
        print(__doc__)
        sys.exit(1)

    # speed-up using multithreads
    cv2.setUseOptimized(True);
    cv2.setNumThreads(4);

    # read image
    im = cv2.imread(sys.argv[1])
    # resize image
    newHeight = 200
    newWidth = int(im.shape[1] * 200 / im.shape[0])
    im = cv2.resize(im, (newWidth, newHeight))

    # create Selective Search Segmentation Object using default parameters
    ss = cv2.ximgproc.segmentation.createSelectiveSearchSegmentation()

    # set input image on which we will run segmentation
    ss.setBaseImage(im)

    # Switch to fast but low recall Selective Search method
    if (sys.argv[2] == 'f'):
        ss.switchToSelectiveSearchFast()

    # Switch to high recall but slow Selective Search method
    elif (sys.argv[2] == 'q'):
        ss.switchToSelectiveSearchQuality()
    # if argument is neither f nor q print help message
    else:
        print(__doc__)
        sys.exit(1)

    # run selective search segmentation on input image
    rects = ss.process()
    print('Total Number of Region Proposals: {}'.format(len(rects)))

    # number of region proposals to show
    numShowRects = 100
    # increment to increase/decrease total number
    # of reason proposals to be shown
    increment = 50

    while True:
        # create a copy of original image
        imOut = im.copy()

        # itereate over all the region proposals
        for i, rect in enumerate(rects):
            # draw rectangle for region proposal till numShowRects
            if (i < numShowRects):
                x, y, w, h = rect
                cv2.rectangle(imOut, (x, y), (x + w, y + h), (0, 255, 0), 1, cv2.LINE_AA)
            else:
                break

        # show output
        cv2.imshow("Output", imOut)

        # record key press
        k = cv2.waitKey(0) & 0xFF

        # m is pressed
        if k == 109:
            # increase total number of rectangles to show by increment
            numShowRects += increment
        # l is pressed
        elif k == 108 and numShowRects > increment:
            # decrease total number of rectangles to show by increment
            numShowRects -= increment
        # q is pressed
        elif k == 113:
            break
    # close image show window
    cv2.destroyAllWindows()
 

效果圖：