Brisque

Color Bar Handling and Tone Repoduction Curve

 Sven Smet
 23- Nov-00

Since Lotem UPD 1.27 the handling of the Colorbar with the Tone Reproduction Curve (TRC) has changed as follows:

Before Lotem upd1.27 colorbars are NOT protected from the TRC
Since Lotem upd 1.27 and above "colorbar" is protected from the TRC

The Brisque will apply the protection from the TRC as follows;

A. mark having in the naming "colorbar" will be protected
B. mark using the SBI convention for spotcolors will be protected if spots are used in the job.
For Example: marker named CB123456 containing cmyk SBI1 SBI2

1. CB123456 applied to a CMYK job will NOT be protected from the TRC because;

a. the name is not containing "colorbar".
b. the SBI convention is not used, there are no spot colors in the job.

2. CB123456 applied to a cmyk+1spot job the job will be protected from the TRC because;

a. the SBI convention is used, there is a spot color in the job The behaviour of the TRC with the colorbar is different if Spot colors are used or not, this obviously is not desirable to most customers.

NOTE: Lotem Upd1.35 (beta) was created due to problems experienced with the protection with VLSI and handling of the colorbar marker, causing double pass and unexposed areas on plates. Upd1.35 with VLSI will ignore the protection of the TRC. With the TSP interface the behaviour will be the same as detailed in the example above.