Implemented an algorithm using opencv to convert a colored image into its negative getting number of pixels in the image converting each pixel's color to its negative read original image convert to its negative show result image
from cv2 import destroyAllWindows, imread, imshow, waitKey


def convert_to_negative(img):
    # getting number of pixels in the image
    pixel_h, pixel_v = img.shape[0], img.shape[1]

    # converting each pixel's color to its negative
    for i in range(pixel_h):
        for j in range(pixel_v):
            img[i][j] = [255, 255, 255] - img[i][j]

    return img


if __name__ == "__main__":
    # read original image
    img = imread("image_data/lena.jpg", 1)

    # convert to its negative
    neg = convert_to_negative(img)

    # show result image
    imshow("negative of original image", img)
    waitKey(0)
    destroyAllWindows()
