This is a photo I took during a recent trip around my city. I first used the "levels adjustments" to restore the grayscale of the color in the photo, and then used the "curves adjustments" to make the color in the photo more vivid and restore the real world. However, it was cloudy, so the shooting effect of the sky was not good. I hoped to restore the sky at that time, so I used the "overlay" and "cropping the mask on adjustments layers" to only restore some of the blues of the sky. And all of these created my final improved version.