Image haze removal is a very essential preprocessing step in machine vision systems. Due to different imaging mechanisms of daytime hazy images and nighttime hazy images (such as different light sources), it is difficult to have a common method to achieve the dehazing effect of daytime and nighttime hazy images at the same time. Therefore, we propose a daytime image dehazing method based on a physical model and image enhancement, and a nighttime hazy image dehazing method based on image enhancement. For daytime hazy images, we propose an image dehazing method with improved dark channel priors, and image enhancement through an improved sparrow search algorithm. For nighttime hazy images, we propose an image dehazing method based on the improved multiple-scale Retinex, and finally use the improved sparrow search algorithm for post-processing to improve the visual effect of dehazing and enhance the details. Quantitative and qualitative experimental results prove that our method can achieve excellent sharpening effects on daytime and nighttime hazy images.