nn.py

"""
nn - function nearest neigbor to map pixels of scaled images to the original images for image interpolation. By default, assume that scale around (0, 0)
Parameters:
	orgi_img	I/P	original image input
	scaled_img	I/P	scaled image input - 2d array of mapped pixels
	h_ratio		I/P	scaling ratio for height
	w_ratio		I/P	scaling ratio for width
			O/P	color-filled image
"""
def nn(origi_img, scaled_img, h_ratio, w_ratio):
	"""
		nearest neighbor - a linear interpolation to fill pixels of scaled images by picking the neartest pixels 
	"""

	#get height and width of scaled_img and origi_img
	height = scaled_img.shape[0]
	h = origi_img.shape[0]
	width = scaled_img.shape[1]
	w = origi_img.shape[1]
	
	#visit each pixel and map back to original image
	for row in range(height):
		x = round(row / h_ratio) 
		if not x in range(h): #if out-of-bound, fill w/ zeros
			continue

		for col in range(width):
			y = round(col / w_ratio)

			#map to the nearest pixels
			if not y in range(w): #if out-of-bound, fill with zero 
				continue
			else:
				scaled_img[row, col] = origi_img[x, y]
	return scaled_img
	"""		end of nn		"""