Generalized Contrast to Noise Ratio

Generalized Contrast to Noise Ratio

Author: Bob Dougherty (rpd@optinav.com)

Installation: Download GCNR_.java or GCNR_.class into the plugins folder. Plugins/Compile and Run... if you downloaded the .java file. Help/Refresh Menus or restart ImageJ.
Description: ImageJ plugin to compute the Generalized Contrast to Noise ratio, gCNR, for 2 ROIs in a 32-bit image.

Usage: For the plugin to run, the ROI Manager must have exactly two ROIS. Choose an image and run GCNR_. The result is a Plot showing the normalized histograms for the ROIS. The value of gCNR is shown in the upper left of the Plot and optionally saved in the Results Table.

Example: The document Generalized_Contast_Noise.pdf shows an example in context of demonstrating a new beamforming algorithm.
History: Version 0: 6/5/2026

License:
Copyright (c) 2026, OptiNav, Inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of OptiNav, Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

ImageJ: ImageJ can be freely downloaded from the ImageJ web site.

Author:	Bob Dougherty (rpd@optinav.com)
Installation:	Download GCNR_.java or GCNR_.class into the plugins folder. Plugins/Compile and Run... if you downloaded the .java file. Help/Refresh Menus or restart ImageJ.
Description:	ImageJ plugin to compute the Generalized Contrast to Noise ratio, gCNR, for 2 ROIs in a 32-bit image.
Usage:	For the plugin to run, the ROI Manager must have exactly two ROIS. Choose an image and run GCNR_. The result is a Plot showing the normalized histograms for the ROIS. The value of gCNR is shown in the upper left of the Plot and optionally saved in the Results Table.
Example:	The document Generalized_Contast_Noise.pdf shows an example in context of demonstrating a new beamforming algorithm.
History:	Version 0: 6/5/2026
License:	Copyright (c) 2026, OptiNav, Inc. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of OptiNav, Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
ImageJ:	ImageJ can be freely downloaded from the ImageJ web site.