import cv2
import numpy as np
import math

def draw_line_P(img, x1, y1, x2, y2, color = (0, 0, 255), thickness = 2,
lineType=cv2.LINE_AA):
    cv2.line(img, (x1, y1), (x2, y2), color, thickness, lineType)

def draw_circle(img, center, radius, color=(0, 0, 255), thickness = 2,
lineType = cv2.LINE_AA):
    cv2.circle(img, center, radius, color, thickness, lineType)

img = cv2.imread("C:\Program Files (x86)\Photos for TZ\6_1.png",cv2.IMREAD_COLOR)
allLines = np.copy(img)
longestLine = np.copy(img)
allCircles = np.copy(img)
biggestCircle = np.copy(img)

img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
img_grayinv = cv2.bitwise_not(img_gray)

lines = cv2.HoughLinesP(img_grayinv, rho = 1, theta = np.pi/720, threshold = 230,
minLineLength=150, maxLineGap = 15)

maxLen = 0
x1P, y1P, x2P, y2P = 0, 0, 0, 0
for line in lines:
    x1, y1, x2, y2 = line[0]
    currentLen = math.sqrt((x2 - x1)**2 + (y2 - y1)**2)
    if currentLen >= maxLen:
        maxLen = currentLen
        x1P, y1P, x2P, y2P = x1, y1, x2, y2
    draw_line_P(allLines, x1, y1, x2, y2)
draw_line_P(longestLine, x1P, y1P, x2P, y2P)

edges = cv2.Canny(img_gray, 0, 255)
circles = cv2.HoughCircles(edges, cv2.HOUGH_GRADIENT, dp = 1, minDist = 250,
param1 = 255, param2 = 97, minRadius = 0, maxRadius = 0)

xmax, ymax, rmax = 0, 0, 0
for circle in circles[0]:
    x0, y0, r = circle
    if r > rmax:
        xmax, ymax, rmax = x0, y0, r
    draw_circle(allCircles, (x0, y0), r)
draw_circle(biggestCircle, (xmax, ymax), rmax)

cv2.imwrite("C:\Program Files (x86)\Photos for TZ\allLines.png", allLines)
cv2.imwrite("C:\Program Files (x86)\Photos for TZ\longestLine.png", longestLine)
cv2.imwrite("C:\Program Files (x86)\Photos for TZ\allCircles.png", allCircles)
cv2.imwrite("C:\Program Files (x86)\Photos for TZ\biggestCircle.png", biggestCircle)