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plotSFR

Plot spatial frequency response of edge

Description

plotSFR(sharpnessMeasurementTable) plots the spatial frequency response (SFR) in a sharpness measurement table or aggregate sharpness measurement table.

example

plotSFR(sharpnessMeasurementTable,Name,Value) plots the SFR, specifying additional parameters to control aspects of the display.

Examples

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This example shows how to display the spatial frequency response (SFR) plot of a specified subset of the 60 slanted edge ROIs on an Imatest® eSFR chart.

Read an image of an eSFR chart into the workspace.

I = imread("eSFRTestImage.jpg");

Create an esfrChart object, then display the chart with ROI annotations. The 60 slanted edge ROIs are labeled with green numbers.

chart = esfrChart(I);
displayChart(chart,displayGrayROIs=false,...
    displayColorROIs=false,displayRegistrationPoints=false)

Figure eSFR test chart contains an axes object. The axes object contains 61 objects of type image, text.

Measure the edge sharpness in all ROIs and return the measurements in sharpnessTable.

sharpnessTable = measureSharpness(chart);

Display the SFR plot of ROIs 26 and 27 only.

plotSFR(sharpnessTable,ROIIndex=[26 27]);

Figure SFR Plots for ROI 26 contains an axes object. The axes object with title ROI 26, xlabel Spatial Frequency (Line pairs per pixel), ylabel SFR (Spatial Frequency Response) contains 8 objects of type line. These objects represent Red Channel, Green Channel, Blue Channel, Luminance Channel, Red Channel Beyond Nyquist, Green Channel Beyond Nyquist, Blue Channel Beyond Nyquist, Luminance Channel Beyond Nyquist.

Figure SFR Plots for ROI 27 contains an axes object. The axes object with title ROI 27, xlabel Spatial Frequency (Line pairs per pixel), ylabel SFR (Spatial Frequency Response) contains 8 objects of type line. These objects represent Red Channel, Green Channel, Blue Channel, Luminance Channel, Red Channel Beyond Nyquist, Green Channel Beyond Nyquist, Blue Channel Beyond Nyquist, Luminance Channel Beyond Nyquist.

Input Arguments

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SFR measurements of edges, specified as a sharpness table or aggregate sharpness table with m rows:

  • When sharpnessMeasurementTable is a sharpness table, m is the number of sampled ROIs.

  • When sharpnessMeasurementTable is an aggregate sharpness table, m is either 1 or 2, corresponding to the number of sampled orientations.

To obtain a sharpness table or aggregate sharpness table, use the measureSharpness function.

Data Types: table

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: plotSFR(myTable,'ROIIndex',2) displays the measured sharpness only of ROI 2.

ROI indices to display, specified as the comma-separated pair consisting of 'ROIIndex' and a scalar or vector of integers in the range [1, 60]. The indices match the ROI numbers displayed by displayChart.

  • When sharpnessMeasurementTable is a sharpness table, by default plotSFR creates only one figure, showing the SFR plot from the first row of the table.

  • When sharpnessMeasurementTable is an aggregate sharpness table, plotSFR ignores the specified ROIIndex, and creates one figure for each row in the table.

Example: 29:32

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Display plot legend, specified as the comma-separated pair consisting of 'displayLegend' and true or false. When displayLegend is true, the SFR plot shows a legend that identifies the different curves on the plot.

Data Types: logical

Display plot title, specified as the comma-separated pair consisting of 'displayTitle' and true or false. When displayTitle is true, the SFR plot shows a title that indicates the individual ROI index or aggregate ROI orientation.

Data Types: logical

Axes handle of the displayed image object, specified as the comma-separated pair consisting of 'Parent' and an axes handle. Parent specifies the parent of the image object created by plotSFR.

Version History

Introduced in R2017b

See Also

Functions

Objects