Lookup Tables and Clipping

Several FIFO properties allow you to change the pixel values of acquired images in ways that may benefit your application. These properties include the cc8BitInputLutProp. Each frame grabber supports only one of these properties. The table below, a subset of Setting FIFO Properties, summarizes the frame grabber support for the cc8BitInputLutProp property.

Clipping and LUT properties (subset of Acquisition properties }
	8500	8600
cc8BitInputLutProp	•	•

This property allows you to adjust and constrain pixel values in the acquired image to a mid-range by clipping (or clamping) high and low pixel values at some threshold. Pixel values less than the lower threshold are set to the lower threshold, and pixel values higher than the high threshold are set to the high threshold. This property also allows you to apply an offset to all pixels before any clipping is done. The resulting image is then passed on to the pel buffer. This property used for this purpose is discussed in the following paragraphs.

The figure below shows graphically how the acquired image pixel values are changed if both the offset and clamp are applied.

Offset and clamp

After the offset is applied, all pixel values are increased by 15. There are no pixel values in the range 0 through 14. After the clamp, all pixels are in the range 15 through 240.