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40 lines
1.2 KiB
40 lines
1.2 KiB
3 years ago
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# import cv2
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# import numpy as np
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from cv2 import addWeighted
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from numpy import zeros,expand_dims,float,uint8,sum,clip
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from function.GrayscaleTrans.BGR2GRAY import rgbToGray
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# prewitt filter
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def prewitt_filter(img, K_size=3):
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gray = rgbToGray(img)
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if len(img.shape) == 3:
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H, W, C = img.shape
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else:
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img = expand_dims(img, axis=-1)
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H, W, C = img.shape
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# 填充0
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pad = K_size // 2
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out = zeros((H + pad * 2, W + pad * 2), dtype=float)
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out[pad: pad + H, pad: pad + W] = gray.copy().astype(float)
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tmp = out.copy()
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out_v = out.copy()
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out_h = out.copy()
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## prewitt 水平方向的核
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Kv = [[-1., -1., -1.],[0., 0., 0.], [1., 1., 1.]]
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## prewitt 竖直方向的核
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Kh = [[-1., 0., 1.],[-1., 0., 1.],[-1., 0., 1.]]
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# filtering
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for y in range(H):
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for x in range(W):
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out_v[pad + y, pad + x] = sum(Kv * (tmp[y: y + K_size, x: x + K_size]))
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out_h[pad + y, pad + x] = sum(Kh * (tmp[y: y + K_size, x: x + K_size]))
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out_v = clip(out_v, 0, 255)
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out_h = clip(out_h, 0, 255)
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out_v = out_v[pad: pad + H, pad: pad + W].astype(uint8)
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out_h = out_h[pad: pad + H, pad: pad + W].astype(uint8)
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dst = addWeighted(out_v, 0.5, out_h, 0.5, 0)
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return dst
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# 读取图像
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# img = cv2.imread('../pic/boy.png')
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# prewitt_filter(img)
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