Inverting video signal on op-amp on positive rail only
As i understand you, you want a circuit to reverse the voltage ramp (inverse the output relative to its maximum voltage).
The following circuit will do this.
Take into account, that a real OpAmp will introduce a phase shift to the signal, thus inducing an oscillation through the feedback paths, so it might be necessary to do some lowpass filtering and gain adjustment there.







simulate this circuit &ndash; Schematic created using CircuitLab

For better understanding of the circuit:
OA1 is a differential amplifier (it will output the difference between the + and - pin).
After this stage there is a Diode and a cap. This is a circuit to find the maximum voltage of the input signal and to keep this voltage "stored" in the cap. To reset the maximum voltage (eg. if you want to switch the system) you just need to press the button to discharge the cap.
OA2 is a follower OpAmp to output the cap's voltage without discharging it too much.
OA4 is a differential amplifier to measure the reverse voltage drop of the diode and it feeds its output to the negative pin of OA1, which results in the addition of the diode voltage drop to the input signal, thus eliminating the bias introduced by the diode
OA3 will then subtract the input signal from its maximum voltage and thus reverse the ramp.