import cv2
import time
import logging

d = 1

while True:
    try:
        threshold = 25
        time.sleep(1)

        input = ('input%d.jpg'%d)
        page = ('page%d.jpg'%d)

        print("Value of d is:",d,"\n","Page name:",input)
        img = cv2.imread(input, 0) # load grayscale version

        # the indeces where the useful region starts and ends
        hStrart = 0
        hEnd = img.shape[0]
        vStart = 0
        vEnd = img.shape[1]

        # get row and column maxes for each row and column
        hMax = img.max(1)
        vMax = img.max(0)

        hDone_flag = False
        vDone_flag = False

        # go through the list of max and begin where the pixel value is greater
        # than the threshold
        for i in range(hMax.size):
            if not hDone_flag:
                if hMax[i] > threshold:
                    hStart = i
                    hDone_flag = True

            if hDone_flag:
                if hMax[i] < threshold:
                    hEnd = i
                    break

        for i in range(vMax.size):
            if not vDone_flag:
                if vMax[i] > threshold:
                    vStart = i
                    vDone_flag = True

            if vDone_flag:
                if vMax[i] < threshold:
                    vEnd = i
                    break

        # load the color image and choose only the useful area from it
        img2 = (cv2.imread(input))[hStart:hEnd, vStart:vEnd,:]

        # write the cropped image
        cv2.imwrite(page, img2)

        d+=1
        print("Value of d is:", d)

    except:
        logging.exception("message")
        print("All pages must be ready!")
        break