手动实现高斯滤波(python)

手动实现高斯滤波

# -*- coding: utf-8 -*-
"""
Created on Sat Jul 11 14:53:28 2020

@author: 陨星落云
"""
import imageio
import numpy as np

def GaussianFilter(img):
    
    h,w,c = img.shape
    # 高斯滤波 
    K_size = 3
    sigma = 1
    
    # 零填充
    pad = K_size//2
    out = np.zeros((h + 2*pad,w + 2*pad,c),dtype=np.float)
    out[pad:pad+h,pad:pad+w] = img.copy().astype(np.float)
    
    # 定义滤波核
    K = np.zeros((K_size,K_size),dtype=np.float)
    
    for x in range(-pad,-pad+K_size):
        for y in range(-pad,-pad+K_size):
            K[y+pad,x+pad] = np.exp(-(x**2+y**2)/(2*(sigma**2)))
    K /= (sigma*np.sqrt(2*np.pi))
    K /=  K.sum()
    
    # 卷积的过程
    tmp = out.copy()
    for y in range(h):
        for x in range(w):
            for ci in range(c):
                out[pad+y,pad+x,ci] = np.sum(K*tmp[y:y+K_size,x:x+K_size,ci])
    
    out = out[pad:pad+h,pad:pad+w].astype(np.uint8)
    
    return out

if __name__ == "__main__":
    
    # 读取图像
    img = imageio.imread("lena.jpg")
    # 高斯滤波
    imageio.imsave("GaussianFilter.jpg",GaussianFilter(img))

结果：