python实现图像增强算法
作者:咸鱼也有翻身日
这篇文章主要为大家详细介绍了python实现图像增强算法,文中示例代码介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
本文实例为大家分享了python实现图像增强算法的具体代码,供大家参考,具体内容如下
图像增强算法,图像锐化算法
1)基于直方图均衡化
2)基于拉普拉斯算子
3)基于对数变换
4)基于伽马变换
5) CLAHE
6) retinex-SSR
7) retinex-MSR
其中,基于拉普拉斯算子的图像增强为利用空域卷积运算实现滤波
基于同一图像对比增强效果
直方图均衡化:对比度较低的图像适合使用直方图均衡化方法来增强图像细节
拉普拉斯算子可以增强局部的图像对比度
log对数变换对于整体对比度偏低并且灰度值偏低的图像增强效果较好
伽马变换对于图像对比度偏低,并且整体亮度值偏高(对于相机过曝)情况下的图像增强效果明显
import cv2 import numpy as np import matplotlib.pyplot as plt # 直方图均衡增强 def hist(image): r, g, b = cv2.split(image) r1 = cv2.equalizeHist(r) g1 = cv2.equalizeHist(g) b1 = cv2.equalizeHist(b) image_equal_clo = cv2.merge([r1, g1, b1]) return image_equal_clo # 拉普拉斯算子 def laplacian(image): kernel = np.array([[0, -1, 0], [-1, 5, -1], [0, -1, 0]]) image_lap = cv2.filter2D(image, cv2.CV_8UC3, kernel) # cv2.imwrite('th1.jpg', image_lap) return image_lap # 对数变换 def log(image): image_log = np.uint8(np.log(np.array(image) + 1)) cv2.normalize(image_log, image_log, 0, 255, cv2.NORM_MINMAX) # 转换成8bit图像显示 cv2.convertScaleAbs(image_log, image_log) return image_log # 伽马变换 def gamma(image): fgamma = 2 image_gamma = np.uint8(np.power((np.array(image) / 255.0), fgamma) * 255.0) cv2.normalize(image_gamma, image_gamma, 0, 255, cv2.NORM_MINMAX) cv2.convertScaleAbs(image_gamma, image_gamma) return image_gamma # 限制对比度自适应直方图均衡化CLAHE def clahe(image): b, g, r = cv2.split(image) clahe = cv2.createCLAHE(clipLimit=2.0, tileGridSize=(8, 8)) b = clahe.apply(b) g = clahe.apply(g) r = clahe.apply(r) image_clahe = cv2.merge([b, g, r]) return image_clahe def replaceZeroes(data): min_nonzero = min(data[np.nonzero(data)]) data[data == 0] = min_nonzero return data # retinex SSR def SSR(src_img, size): L_blur = cv2.GaussianBlur(src_img, (size, size), 0) img = replaceZeroes(src_img) L_blur = replaceZeroes(L_blur) dst_Img = cv2.log(img/255.0) dst_Lblur = cv2.log(L_blur/255.0) dst_IxL = cv2.multiply(dst_Img, dst_Lblur) log_R = cv2.subtract(dst_Img, dst_IxL) dst_R = cv2.normalize(log_R,None, 0, 255, cv2.NORM_MINMAX) log_uint8 = cv2.convertScaleAbs(dst_R) return log_uint8 def SSR_image(image): size = 3 b_gray, g_gray, r_gray = cv2.split(image) b_gray = SSR(b_gray, size) g_gray = SSR(g_gray, size) r_gray = SSR(r_gray, size) result = cv2.merge([b_gray, g_gray, r_gray]) return result # retinex MMR def MSR(img, scales): weight = 1 / 3.0 scales_size = len(scales) h, w = img.shape[:2] log_R = np.zeros((h, w), dtype=np.float32) for i in range(scales_size): img = replaceZeroes(img) L_blur = cv2.GaussianBlur(img, (scales[i], scales[i]), 0) L_blur = replaceZeroes(L_blur) dst_Img = cv2.log(img/255.0) dst_Lblur = cv2.log(L_blur/255.0) dst_Ixl = cv2.multiply(dst_Img, dst_Lblur) log_R += weight * cv2.subtract(dst_Img, dst_Ixl) dst_R = cv2.normalize(log_R,None, 0, 255, cv2.NORM_MINMAX) log_uint8 = cv2.convertScaleAbs(dst_R) return log_uint8 def MSR_image(image): scales = [15, 101, 301] # [3,5,9] b_gray, g_gray, r_gray = cv2.split(image) b_gray = MSR(b_gray, scales) g_gray = MSR(g_gray, scales) r_gray = MSR(r_gray, scales) result = cv2.merge([b_gray, g_gray, r_gray]) return result if __name__ == "__main__": image = cv2.imread('img/FJ(93).png') image_gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) plt.subplot(4, 2, 1) plt.imshow(image) plt.axis('off') plt.title('Offical') # 直方图均衡增强 image_equal_clo = hist(image) plt.subplot(4, 2, 2) plt.imshow(image_equal_clo) plt.axis('off') plt.title('equal_enhance') # 拉普拉斯算法增强 image_lap = laplacian(image) plt.subplot(4, 2, 3) plt.imshow(image_lap) plt.axis('off') plt.title('laplacian_enhance') # LoG对象算法增强 image_log = log(image) plt.subplot(4, 2, 4) plt.imshow(image_log) plt.axis('off') plt.title('log_enhance') # # 伽马变换 image_gamma = gamma(image) plt.subplot(4, 2, 5) plt.imshow(image_gamma) plt.axis('off') plt.title('gamma_enhance') # CLAHE image_clahe = clahe(image) plt.subplot(4, 2, 6) plt.imshow(image_clahe) plt.axis('off') plt.title('CLAHE') # retinex_ssr image_ssr = SSR_image(image) plt.subplot(4, 2, 7) plt.imshow(image_ssr) plt.axis('off') plt.title('SSR') # retinex_msr image_msr = MSR_image(image) plt.subplot(4, 2, 8) plt.imshow(image_msr) plt.axis('off') plt.title('MSR') plt.show()
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。