By “individual frames”, I take it you mean that the footage is already on you computer. If this is the case then easy, I do this all the time… hey if anythings worth doing, then it’s worth doing frame by frame.
Use Photoshop and either Premiere Pro or Final Cut Pro. In Final Cut make a new sequence, then copy and paste your clip you need the frames from into new sequence then export your sequence using Quicktime conversion as individual frames. Import the frames into Photoshop and go about your business, however many frames you edit re-import these back into Final Cut and put them above your previous sequence clip in the right places. In Premiere you just export frame and it is the same process.
