Load the movie into your editing application. You need a program that exports image sequences. Set in-and-out points to the range you want to convert. Add a little bit of extra time at the beginning and the end so that you have the option to trim the clip later.
Export your clip as an image sequence. Create a folder on your computer to hold all of the frames, and export using such file types as .PNG or .TGA. These formats will retain high quality.
Open Adobe Photoshop. Instead of manually adjusting each frame, you are going to tell Photoshop how to automate the process. Open the first frame of your image sequence into Photoshop.
Before you adjust anything, click on "Window" up in the toolbar and select "Actions." This will open a list of default actions Photoshop has been programmed to do. On the bottom of the actions window, click on the icon that looks like a page curl and is adjacent to the garbage pail icon to create a new action.
Type in a name for your action, such as "cartoon effect" or something similar that will let you identify it from the list. Click on "Record." Photoshop is now recording the actions that you take.
Select "Filter" from the top menu. Highlight "Artistic" and select "Poster Edges." This will add dark outlining to your image and will already being to look like a cartoon. Adjust the settings until you get as close as you can to the look you want. Click on "OK" to apply the effect.
Go back to "Filter," and highlight "Artistic" and, this time, select "Cutout." This will help you achieve the painted look. Play around with the settings, particularly with the "Edge Simplicity" slider. The higher you make this value, the closer to a cartoon it will begin to look. When you are happy with the results, click on "OK" to apply it.
You should now have an image that looks like an animated version of the movie you started with. Go to "File" and select "Save As." Pick a destination folder and save as either a .PNG or .TGA. Go back to the actions window and select the "Stop" button on the bottom left of the window. Your action name should now appear in the list, and Photoshop has just "learned" the filter you want to apply.
Go to "File," highlight "Automate" and select "Batch." In the drop-down list next to "Action," select the name of the action you just recorded. Choose the source folder where your frames have been exported to and hit "OK." Choose a destination folder to store the finished converted frames. Do not use the same destination folder as your source or your images will mix up or overwrite.
Click on "OK" when you are done, and Photoshop will open each image, apply your filters, save the image, close it and then repeat the process with the next image. You may want to step away from the computer for a while as this process can take a very long time.
Return to your editing application and go to your import settings. Navigate to the destination directory, which should now contain all of your converted frames. Select the first image, and look for an import setting that says "Detect Sequential Images" or something similar. This will tell the application to combine all the frames into one video clip.
Your clip is now imported and ready for editing. You have successfully converted a movie into a cartoon.