If you want the “best possible results” I would recommend the following workflow, or similar variation thereof:
Export your captured video source to a JPG Image Sequence. This will create a JPG for each discrete frame of the video. If you want ultimate color control, with no loss of quality due to JPG compression, you can export instead a TIF sequence, but the size of your output will be 30-50 times larger for HD content.
Second, using Photoshop, open a single frame.
Being your camera is a lockdown shot, choose your reference pixel to be used to determine brightness. I would recommend picking a pixel that has a luminance value of medium grey.
Save your Frame as “Reference.jpg”
Close the File.
Now open a new different frame from the JPG sequence.
Record an Action Sequence that:
1) Opens Reference.jpg. Then uses the Adobe Keyboard command for select previous document.
2) Uses the Match Color Edit Command -> Under Edit Tab
3) Grabs the color value on the open new frame (the one you just opened).
4) Matches the color value to the Reference.jpg file for the exact same reference area.
5) Youll have to play with the parameters adjusting Fuzziness, Threshold, Etc, to get the settings right.
6) Apply Match Color Command.
7.) Close Reference.jpg
8.) End Recording of Action Sequence.
Then... Use Image Processor within Bridge to Batch your JPG Sequence Files. Select your input directory, output directory, and check th box “Run Action on Processed Files” - Select the Recorded Action.
Run the Image Processor.
This will give you the best possible results, specifically if you use TIF and work in a 16 Bit Workspace.
Hope this helps.