GUI utilities - ISET/isetcam GitHub Wiki

• Image processing
• Sensor

This page describes some commonly used, and occasionally quite helpful, utilities that interact with the ISETCam windows: plotting and data selection routines that simplify certain types of analysis and help with code debugging. Each of the major structures has an interface program with multiple options, structured in a regular way: scenePlot, oiPlot, sensorPlot, ipPlot.

Plot windows store their underlying data in the figure's UserData, so you can pull the plotted numbers back out programmatically rather than reading them off the screen:

hdl = scenePlot(scene,'illuminant photons');   % hdl is the figure handle
udata = get(hdl,'UserData');                   % The plotted data

The same pattern applies to oiPlot, sensorPlot, and ipPlot.

The Macbeth Color Checker (MCC), also called the Gretag color checker, is widely used in color analysis and calibration. ISETCam has utilities that simplify finding the 24 patches and analyzing the data within them; these work with MCC data in the sensor and ip windows, and are being extended to the scene and optical image windows. Locate them with macbeth<TAB>, including macbethSelect, macbethChartCreate, and macbethDrawRects. ipSet(ip,'conversion method sensor','MCC Optimized') (see Image processing methods) relies on these tools to fit a sensor-to-color-space transform from an imaged MCC.

Each ISETCam window supports selecting a region of interest (ROI) directly on the displayed image, for computing statistics or extracting data from just that region. ieROISelect and vcROISelect handle interactive selection; ieROIDraw draws a specified ROI shape onto a window's axes programmatically. t_ROIDraw (see Tutorials) walks through drawing ROI shapes on ISETCam window axes.

The ISO 12233 standard defines how to measure a system's spatial frequency response (MTF) from an image of a slanted edge. sceneCreate('slanted bar') (or the lower-level sceneSlantedBar) creates the target; ISO12233/ieISO12233 compute the MTF from an image of it. In the ip window, the same calculation is available from the pulldown menus: Analyze > Create Slanted Bar, then Analyze > ISO12233. See s_sceneSlantedBar and s_metricsMTFSlantedBar in Examples for scripted versions.