The Four Quadrant Tone Reproduction Curve (The "Jones Plot")

The System involves Three TTFs Camera Monitor Processor LoLo pixel value, P c Luminance, L c pixel value, P m

The three TTFs combine to make one SYSTEM TTF. We want the overall SYSTEM TTF to make the best possible image. LoLo pixel value, P c Luminance, L c pixel value, P m LcLc LoLo 0 0 L max IwIw How do we design the Processor TTF? We construct a Jones Plot.

Assume we know the camera TTF. Assume we know the monitor TTF. PcPc LoLo PmPm LcLc LoLo pixel value, P c Luminance, L c pixel value, P m

Assume we DEFINE the desired SYSTEM TTF. LoLo LcLc LoLo pixel value, P c Luminance, L c pixel value, P m PmPm PcPc ??? How do we figure out what the DIP TTF should be??

LoLo LcLc Place the TTFs into four quadrants as follows…………….. LoLo pixel value, P c Luminance, L c pixel value, P m

I L PcPc I PmPm L (I) Camera (III) Monitor (IV) SYSTEM (II) Processor ??? (required) (set by OEM)

Flip around horizontal axis… I L (I) Camera (III) Monitor (IV) SYSTEM (II) Processor PcPc I PmPm L ???

…so that values increase as you go to the right and down. I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor ???

Flip around vertical axis… I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor ???

…so the values increase up and to the left. I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor ???

Find the missing TTF by tracing around the graph. I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor

I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor

I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor

I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor

I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L (II) Processor

I L (I) Camera (III) Monitor (IV) SYSTEM PcPc I PmPm L Sketch in the remainder of the TTF. (II) Processor

PcPc PmPm Clear out everything else, and what is left is a flipped version of the missing TTF. (II) Processor 0 0

PcPc PmPm Un-flip the coordinates to produce the final TTF for the Processor. PcPc PmPm

Light, I I w = 10,000 lux pixel value, P c Luminance, L pixel value, P m PcPc PmPm The Required Processor TTF 0 0

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