图像过曝或曝光不足时需要曝光处理，
这里以曝光不足举例。

直方图均衡法：

通过RGB通道的直方图均衡达到处理曝光不足的效果。

代码：

underexpose = cv2.imread("exposure_test.jpg")
#underexpose = cv2.cvtColor(underexpose, cv2.COLOR_BGR2RGB)
equalizeUnder = np.zeros(underexpose.shape, underexpose.dtype)
equalizeUnder[:, :, 0] = cv2.equalizeHist(underexpose[:, :, 0])
equalizeUnder[:, :, 1] = cv2.equalizeHist(underexpose[:, :, 1])
equalizeUnder[:, :, 2] = cv2.equalizeHist(underexpose[:, :, 2])
cv2.imshow(equalizeUnder)

CNN方法

Learning Multi-Scale Photo Exposure Correction（CVPR2021）
paper
python版github地址

按github配置环境，下载weight.

with torch.no_grad():MSPEC_net = MSPEC_Net().cuda()MSPEC_net =torch.nn.DataParallel(MSPEC_net)MSPEC_net.load_state_dict(torch.load('./snapshots/MSPECnet_woadv.pth'))MSPEC_net.eval()data_input = cv2.imread('test.jpg')output_image = down_correction(MSPEC_net,data_input) #在mspect_test.py中if output_image.dtype == 'uint8':cv2.imwrite( "output.jpg",output_image)else:cv2.imwrite( "output.jpg",output_image*255)