Step 1: Note we exaggerated the distortion in Xin Wang’s original image for Step 1 so that you could see the effect more clearly.
Open your image in Photoshop, and go to Filter > Lens Correction. On the right side of the screen, you’ll see two tabs: Auto Correction and Custom. Start with Auto, which is automatically selected. In the image for this step, no correction has been applied yet, and the picture has all kinds of distortion. The shelves appear bowed out and crooked, and it appears that the camera was not facing them head on.