作法: 使用matlab，將原圖的3個channel(RGB)分離並個別做histogram equalization後合併

code file: ./1_answer.m
input file: 
	./0_before_left_dark.jpg
	./0_before_left_light.jpg
	./0_before_right_dark.jpg
	./0_before_right_light.jpg
original_histogram:
	./1_before_left_dark_histogram.jpg
	./1_before_left_light_histogram.jpg
	./1_before_right_dark_histogram.jpg
	./1_before_right_light_histogram.jpg
output_photo:
	./1_after_left_dark.jpg
	./1_after_left_light.jpg
	./1_after_right_dark.jpg
	./1_after_right_light.jpg
new_histogram:
	./1_after_left_dark_histogram.jpg
	./1_after_left_light_histogram.jpg
	./1_after_right_dark_histogram.jpg
	./1_after_right_light_histogram.jpg