ECE558 Project1 Problem 1

import cv2
import argparse
import numpy as np
from matplotlib import pyplot as plt

# function to find neighbourDirections
def getNeighbourDirections(type_of_neighbours):
    if type_of_neighbours == 'left':
        return [0,-1]
    if type_of_neighbours == 'right':
        return [0,1]
    if type_of_neighbours == 'top':
        return [-1,0]
    if type_of_neighbours == 'bottom':
        return [1,0]
    if type_of_neighbours == 'top-left':
        return [-1,-1]
    if type_of_neighbours == 'top-right':
        return [-1,1]
    if type_of_neighbours == 'bottom-left':
        return [1,-1]
    if type_of_neighbours == 'bottom-right':
        return [1,1]


# function to plot histogram for grayscale image
def plotHist(img):

    y, x = img.shape
    compute = np.zeros([y,x])
    img = img.astype(np.int16)
    i = 0
    while(i < y):
        j = 0
        while(j < x):
            if(i+neighbourDirections[0]>=0 and j+neighbourDirections[1]>=0 and i+neighbourDirections[0]<y and j+neighbourDirections[1]<x):
                compute[i][j] = (img[i][j]-img[i+neighbourDirections[0]][j+neighbourDirections[1]]) ^ 2
            j += 1
        i += 1
    plt.hist(compute.flatten(), bins=np.arange(255))
    plt.show()

# function to plot histogram for image with 3 channels
def plotHist3d(img):

    y, x, c= img.shape
    compute = np.zeros([y,x])
    img = img.astype(np.int16)
    i = 0
    while(i < y):
        j = 0
        while(j < x):
            if(i+neighbourDirections[0]>=0 and j+neighbourDirections[1]>=0 and i+neighbourDirections[0]<y and j+neighbourDirections[1]<x):
                compute[i][j] += (img[i][j][0]-img[i+neighbourDirections[0]][j+neighbourDirections[1]][0]) ^ 2
                compute[i][j] += (img[i][j][1]-img[i+neighbourDirections[0]][j+neighbourDirections[1]][1]) ^ 2
                compute[i][j] += (img[i][j][2]-img[i+neighbourDirections[0]][j+neighbourDirections[1]][2]) ^ 2
            j += 1
        i += 1

    plt.hist(compute.flatten(), bins=np.arange(256))
    plt.show()

# driver code
parser = argparse.ArgumentParser(description='Visualizing and checking the smoothness prior')
parser.add_argument('-i', action='store', dest='img_path',help='Enter image path (relative path)')
parser.add_argument('-n', action='store', dest='type_of_neighbours',help='Enter type of neighbours to process')
args = parser.parse_args()
img_path = args.img_path
type_of_neighbours = args.type_of_neighbours
neighbourDirections = getNeighbourDirections(type_of_neighbours)

imgColor = cv2.imread(img_path)
imgGray = cv2.cvtColor(imgColor, cv2.COLOR_BGR2GRAY)
hsv = cv2.cvtColor(imgColor, cv2.COLOR_BGR2HSV)
lab = cv2.cvtColor(imgColor, cv2.COLOR_BGR2LAB)
plotHist(imgGray)
plotHist3d(imgColor)
plotHist3d(hsv)
plotHist3d(lab)