backend.py

from scipy.spatial import distance as dist
from imutils import perspective
from imutils import contours
import numpy as np
import imutils
import cv2


def midpoint(ptA, ptB):
    return (ptA[0] + ptB[0]) * 0.5, (ptA[1] + ptB[1]) * 0.5


def MakeImageAnalysisGreatAgain(path_to_file, width_of_the_first_element):
    result = []
    image = cv2.imread(path_to_file)

    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    gray = cv2.GaussianBlur(gray, (7, 7), 0)

    edged = cv2.Canny(gray, 50, 100)
    edged = cv2.dilate(edged, None, iterations=1)
    edged = cv2.erode(edged, None, iterations=1)

    cnts = cv2.findContours(edged.copy(), cv2.RETR_EXTERNAL,
                            cv2.CHAIN_APPROX_SIMPLE)
    cnts = imutils.grab_contours(cnts)

    (cnts, _) = contours.sort_contours(cnts)
    pixelsPerMetric = None

    for c in cnts:
        if cv2.contourArea(c) < 100:
            continue
        orig = image.copy()
        box = cv2.minAreaRect(c)
        box = cv2.cv.BoxPoints(box) if imutils.is_cv2() else cv2.boxPoints(box)
        box = np.array(box, dtype="int")

        box = perspective.order_points(box)
        cv2.drawContours(orig, [box.astype("int")], -1, (0, 0, 0), 2)
        cv2.drawContours(orig, [box.astype("int")], -1, (255, 255, 255), 1)


        (tl, tr, br, bl) = box
        (tltrX, tltrY) = midpoint(tl, tr)
        (blbrX, blbrY) = midpoint(bl, br)

        (tlblX, tlblY) = midpoint(tl, bl)
        (trbrX, trbrY) = midpoint(tr, br)


        dA = dist.euclidean((tltrX, tltrY), (blbrX, blbrY))
        dB = dist.euclidean((tlblX, tlblY), (trbrX, trbrY))

        if pixelsPerMetric is None:
            pixelsPerMetric = dB / width_of_the_first_element

        dimA = dA / pixelsPerMetric
        dimB = dB / pixelsPerMetric

        cv2.putText(orig, "{:.1f}cm".format(dimA),
                    (int(tltrX - 15), int(tltrY - 10)), cv2.FONT_HERSHEY_SIMPLEX,
                    0.65, (0, 0, 0), 2)
        cv2.putText(orig, "{:.1f}cm".format(dimB),
                    (int(trbrX + 10), int(trbrY)), cv2.FONT_HERSHEY_SIMPLEX,
                    0.65, (0, 0, 0), 2)
        cv2.putText(orig, "{:.1f}cm".format(dimA),
                    (int(tltrX - 15), int(tltrY - 10)), cv2.FONT_HERSHEY_SIMPLEX,
                    0.65, (255, 255, 255), 1)
        cv2.putText(orig, "{:.1f}cm".format(dimB),
                    (int(trbrX + 10), int(trbrY)), cv2.FONT_HERSHEY_SIMPLEX,
                    0.65, (255, 255, 255), 1)
        result.append(orig)
    return result