How to detect randomly curved non-continuous fixed colored lines from an image?

Question

I am very new in the python openCV. I wanted to find the 7 fixed colored randomly curved lines from an image. The result should be boolean which will give me if the image contains the 7 fixed colored randomly curved lines or not. The sample input image is as below:

I also wanted to find out the non-continuous faint green colored trapezium from the image. I have written the below code to filter out the specific color from the image but unable to detect the lines & unable to conclude if the image is containing the 7 different lines & trapezium. Below is my sample code for the same:

import cv2
import numpy as np

boundaries = [
    (32, 230, 32),   # 2 Green lines
    (10, 230, 230),  # 1 Yellow line
    (230, 72, 32),   # 1  Blue line
    (255, 255, 255), # 2 White lines
    (32, 72, 230)    # 1 Red line
]

box = [(0, 100, 0), (100, 255, 100)]

image = cv2.imread('testImage5.png')

image = removeBlackBands(image)
# cv2.imshow('Cropped Image', image)
# cv2.waitKey(0)

for row in boundaries:
    # create NumPy arrays from the boundaries
    row = np.array(row, dtype="uint8")

    mask = cv2.inRange(image, row, row)
    cv2.GaussianBlur(mask, (5,5), 0)
    cv2.imshow('Filtered', mask)
    cv2.waitKey(0)

    lines = cv2.HoughLinesP(mask, cv2.HOUGH_PROBABILISTIC, np.pi / 180, 50, 50, 100)
    if lines is not None:
        for x in range(0, len(lines)):
            print("line ", x)
            for x1, y1, x2, y2 in lines[x]:
                print("x1 = {}, y1 = {}, x2 = {}, y2 = {}".format(x1, y1, x2, y2))
                cv2.line(image,(x1,y1),(x2,y2),(0,0, 255),2, cv2.LINE_AA)
                pts = np.array([[x1, y1], [x2, y2]], np.int32)
                cv2.polylines(image, [pts], True, (0, 255, 0))

    cv2.imshow('Processed.jpg', image)
    cv2.waitKey(0)

# create NumPy arrays from the boundaries
lower = np.array(box[0], dtype="uint8")
upper = np.array(box[1], dtype="uint8")

# find the colors within the specified boundaries and apply
# the mask
mask = cv2.inRange(image, lower, upper)
output = cv2.bitwise_and(image, image, mask=mask)
output = cv2.cvtColor(output, cv2.COLOR_BGR2GRAY)
output = cv2.Canny(output, 100, 150)
# show the images
# cv2.imshow("output", output)
# cv2.waitKey(0)
cv2.destroyAllWindows()

Can somebody help me? Thanks in Advance..!!!

score 0 · Accepted Answer · answered Dec 25 '19 at 14:06

This is the function I wrote for the same.

def detectNodes(self, image, tolerance=0):
"""
Detect the nodes in the image
Algorithm used:
    1. Pre-process the image to filter out the required color
    2. Convert the pre-processed image to binary image

Args:
    image(np.ndarray): Numpy Nd array of image
    tolerance: (int): Margin of consideration while extracting color from image. Default: 0

Returns
    True upon success, False otherwise

"""
noOfNodesDetected = 0
curveWidth = 2
noOfNodeDetectThreshold = 5

cropH = self.testData["nodalROI"].get("height")
cropW = self.testData["nodalROI"].get("width")
roiImage = ppu.crop(image, cropH, cropW)  # Crop node ROI

for color in self.nodalColorBoundaries.keys():
    filtered = ImageProc.colorFilter(roiImage, colors=self.nodalColorBoundaries[color], tolerance=tolerance)
    bgrImage = ppu.convertColorSpace(filtered, "bgr_to_gray")
    thresh = ppu.threshold(bgrImage, 1, "thresh_binary")

    logging.info("The shape of image is [{}]".format((thresh.shape)))
    height, width = thresh.shape

    pointFraction = self.testData.get("pointsToFormEquationOfCurve", None)
    points = [int(fraction * height) for fraction in pointFraction]
    logging.info("Point using for formulating the equation are [{}]".format(points))
    pointFractionEvaluation = self.testData.get("pointsForEvaluationOfCurve", None)
    pointsForEvaluation_h = [int(fraction * height) for fraction in pointFractionEvaluation]
    logging.info("Point using for Evaluating the equation are [{}]".format(pointsForEvaluation_h))

    curve1 = []
    curve2 = []
    for point in points:
        prevX = 0
        flag = 0
        for w in range(0, width):
            if thresh[point][w] == 255:
                if (abs(prevX - w)) > curveWidth:
                    if flag == 0:
                        curve1.append((point, w))
                        flag = 1
                    else:
                        curve2.append((point, w))
                prevX = w

    fitter = CurveFitter1D()
    if curve2:
        logging.error("Second curve detected with color {} having points {}".format(color, curve2))

    if curve1:
        x1 = [point[0] for point in curve1]
        y1 = [point[1] for point in curve1]
        logging.qvsdebug("Points using to find the Polynomial with color {} are {} ".format(color, curve1))
        fitter._fit_polyfit(x1, y1, 4)
        logging.qvsdebug("Coefficient of the Polynomial with color {} are {} ".format(
            color, fitter._fitterNamespace.coefs))
    else:
        logging.error("Points not found with {}".format(color))
        return False

    pointsForEvaluation_w = [int(round(fitter._predY_polyfit(point))) for point in pointsForEvaluation_h]

    logging.qvsdebug(
        "Points using for the verification of Polynomial representing curve with color {} are {} ".format(
            color, zip(pointsForEvaluation_h, pointsForEvaluation_w)))
    counter = 0
    for i in range(len(pointsForEvaluation_h)):
        if pointsForEvaluation_w[i] + 2 >= width:
            continue  # Continue if control is reaching to width of iamge - 2
        if any(thresh[pointsForEvaluation_h[i]][pointsForEvaluation_w[i] - 2:pointsForEvaluation_w[i] + 3]):
            counter += 1
    logging.info(
        "Out of {} points {} points are detected on the curve for color {}".format(len(pointsForEvaluation_h),
                                                                                   counter, color))
    nodeDetectThreshold = int(len(pointsForEvaluation_h) * 0.6)
    if counter >= nodeDetectThreshold:
        noOfNodesDetected += 1

if noOfNodesDetected >= noOfNodeDetectThreshold:
    logging.info("Nodes found in this frame are [%d], minimum expected [%d]" % (
        noOfNodesDetected, noOfNodeDetectThreshold))
    return True
else:
    logging.error("Nodes found in this frame are [%d], minimum expected is [%d]" % (
        noOfNodesDetected, noOfNodeDetectThreshold))
    return False

How to detect randomly curved non-continuous fixed colored lines from an image?

1 Answers1