Entities (Objects) > Bitmap > Improved Bitmap Mode

The contrast (marked gray levels) can be adjusted by the Mark Speed, by the Dither Step and by the System PixelMap. Before adjusting the System PixelMap for non linearities and White Level, it is recommended to set the Black Level first.

Black Level: Black Level can be adjusted by the Mark Speed and by the Dither Step.

The Black Level is adjusted based on the bitmap marking result of pure black areas (grayscale level = 0). To achieve the shortest process times, the laser power should be set to the maximum value for pure black (System PixelMap and Pen PixelMap map grayscale value 0 to 0). The Black Level can be considered as laser time per area:

To maintain the ratio of the pixel distances in X and Y when adjusting the Black Level, the Mark Speed and the Dither Step are changed with the same factor. This factor which needs to be multiplied with the current values of the Mark Speed and the Dither Step to obtain the new values for the next test marking can be calculated as follows:

Black Level	Adjustment of the Parameters
Not dark enough	Increase laser time per area, for example to 200 % by •decreasing Mark Speed with the factor 71 % •decreasing Dither Step with the factor 71 %
Perfect dark value	Done.
Too dark	Decrease laser time per area, for example to 80 % by •increasing Mark Speed with the factor 112 % •increasing Dither Step with the factor 112 %

Black Level

Adjustment of the Parameters

Not dark enough

Increase laser time per area, for example to 200 % by

•decreasing Mark Speed with the factor 71 %

•decreasing Dither Step with the factor 71 %

Perfect dark value

Done.

Too dark

Decrease laser time per area, for example to 80 % by

•increasing Mark Speed with the factor 112 %

•increasing Dither Step with the factor 112 %

Table 26: Adjust Black Level

White Level: The White Level can be adjusted by the System PixelMap. Only needed for Grayscale Bitmaps.

The System PixelMap does not only configure the White Level but also compensates for non-linearities. However, this will not be discussed further here.

The White Level is adjusted based on the bitmap marking result of pure white (grayscale level 255) and different bright areas.

White Level	Adjustment of the Parameters
Pure white is invisible, but different bright areas are indistinguishable.	Decrease "Out" bit value corresponding to "In 255" bit (white) of the System PixelMap.
A good trade-off between being able to distinguish between different bright areas and the invisibility of pure white.	Done.
Different bright areas are distinguishable, but pure white is too dark.	Increase "Out" bit value corresponding to "In 255" bit (white) of the System PixelMap.

Table 27: Adjust White Level