def METHOD_NAME(self, cam_img):
    '''
    get the horizontal index of the color at the given slice of the image
    input: cam_image, an RGB numpy array
    output: index of max color, value of cumulative color at that index, and mask of pixels in range
    '''
    # take a horizontal slice of the image
    iSlice = self.scan_y
    scan_line = cam_img[iSlice : iSlice + self.scan_height, :, :]
    # convert to HSV color space
    img_hsv = cv2.cvtColor(scan_line, cv2.COLOR_RGB2HSV)
    # make a mask of the colors in our range we are looking for
    mask = cv2.inRange(img_hsv, self.color_thr_low, self.color_thr_hi)
    # which index of the range has the highest amount of yellow?
    hist = np.sum(mask, axis=0)
    max_yellow = np.argmax(hist)
    return max_yellow, hist[max_yellow], mask