This guide explains how to perform a correct intensity range setting and all the related adjustment operations needed to improve the image visualization.
Using intensity range and visualization settings
Basic concepts
Dynamic Range
The dynamic range of the image represents the number of discrete values (Gray Levels) that make up the numerical scale used for the conversion of the analog signal into its digital form. The gray scale has several predefined ranges (8bit-256 GL, 12bit- 4096 GL, 16bit-65356 GL). The range is also called Bit-depth.
The dynamic range of the image is determined by the physical features of the acquisition device used.
Full Dynamic Range
By default, the full dynamic range is mapped on the monitor screen for visualization purpose (Display Range). This means that when the Intensity range is described by few grey levels, a dim or an almost black image is displayed. The intensity information is there but the observer cannot distinguish the image details.
Partial Dynamic Range
Using the dedicated controls, only parts of the dynamic range can be mapped on the monitor screen (Display Range). This operation allows a better distribution of the real signal over the Display Range improving the details visualization.
Color scalebar
arivis Vision4D User Interface shows a Color Bar for each channel present in the dataset (The channel visibility must be set ON). The Color Bar usage has several purposes, one of them is the Dynamic Range optimal mapping with respect to the Display Range.
By dragging the top and bottom slider along the Color Bar, the Dynamic Range can be freely set.
Right-Click on the slider. The top or bottom range value can be entered manually
The Dynamic range of each available channel can be adjusted independently.
The Dynamic range changing does not influence the intensity measurements.
By pressing the Auto button, arivis Vision4D computes the best Dynamic range setting based on the active Z plane intensity distribution (Histogram).
The active Z plane can be changed using the Navigator panel controls. Please refer to the (arivis Vision4D Help) for more details.
Right-Click on the Auto button. A pop-up menu is displayed. Select the Global auto color item to compute the best Dynamic Range setting based on all the Z planes Histograms.