In Adobe Photoshop, you can edit video frames, or even paint directly on them—a process known as rotoscoping. One method is to first export the video frames from your video application in filmstrip format.

From some video editing and compositing applications such as Adobe Premiere Pro (Windows only) and After Effects, you can export part or all of a composition, sequence, or clip as a single filmstrip file. Because video compression isn’t used in creating filmstrip files, they can be large. If your computer doesn’t have enough memory for Photoshop to load the filmstrip file, you can break the file into any number of smaller files by setting the work area to a different portion of the composition or sequence before rendering or exporting each portion, or you can export the composition, clip, or sequence as numbered still images so that you can edit each frame as a separate file.

A filmstrip opens in Adobe Photoshop as a series of frames in a column, with each frame labeled by number, reel name, and timecode. If the column created by the filmstrip frames is more than 30,000 pixels tall, the frames continue in a second column. The number of frames displayed depends on the duration of the footage or clip and the frame rate selected when you render the filmstrip.

When editing a filmstrip in Adobe Photoshop, use the following guidelines for best results:

• After Effects and Adobe Premiere Pro display only the part of each frame that lies within the frame border; however, you can paint on the gray lines dividing the frames of the filmstrip without damaging the file.

• You can edit the red, green, blue, and alpha channels in the filmstrip file. Use only channel 4 as the alpha channel; other alpha channels aren’t recognized.

• Don’t resize or crop the filmstrip.

• Flatten any layers you add in Adobe Photoshop.