import cv2
 
def getImageVar(imgPath):
  image = cv2.imread(imgPath)
  img2gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
  imageVar = cv2.Laplacian(img2gray, cv2.CV_64F).var()
  return imageVar
 
imageVar = getImageVar("./lena.jpg")
print(imageVar)

def is_color_image(url):
  im=Image.open(url)
  pix=im.convert('RGB')
  width=im.size[0]
  height=im.size[1]
  oimage_color_type="Grey Image"
  is_color=[]
  for x in range(width):
    for y in range(height):
      r,g,b=pix.getpixel((x,y))
      r=int(r)
      g=int(g)
      b=int(b)
      if (r==g) and (g==b):
        pass
      else:
        oimage_color_type='Color Image'
  return oimage_color_type

void calculate_average_brightness(const unsigned char* image, const int width, const int height, double* brightness) {
  int length = width * height;
  double sum;
  for (int i = 0; i < length; ++i) {
    sum += image[i];
  }
  brightness = sum / length; // brightness value: [0, 255]
}