If your photos are crooked, they can look very distracting when edited together with your video. Thin, crooked lines look very poor, in fact they can vibrate or flicker on-screen. If a photo is not straight (because it was shot at a slight angle), it is easy to fix.
- In Photoshop, select the Ruler Tool (I).
- Locate a line or surface that you think should be horizontal (or vertical).
- Click and drag a line to measure the angle.
- In the Options bar click the Straighten button.
- The correct value is used to rotate the image and it is automatically cropped to avoid any gaps at the edges.
For more on Photoshop check out Understanding Adobe Photoshop and Photoshop for Video.