To outline an image in Photoshop, you can follow these steps:
1. Open the image you wish to outline in Photoshop.
2. Select the subject or object you want to outline using a selection tool, such as the Quick Selection Tool or the Magic Wand Tool.
3. Double click on your layer to open the Layer Styles panel. Select the “Stroke” style and set the stroke type to “Outside”.
4. Adjust the color and width of your outline to suit your preference.
5. Save the image.
Here is a tutorial that explains these steps in more detail: