Hoku is a Java-based software package to process multispectral image data sets

to recover writings that have been damaged or erased.  It is distributed free-of-charge,

without warranty.  The current version is 1.9.3, released on 6 December 2022.


Installing Hoku


Download the InstallHoku.jar file to your computer’s Desktop.
On the Desktop, double-click on the InstallHoku.jar icon to start the process.


<-- Select to download InstallHoku.jar.




Double-click on the downloaded InstallHoku.jar file.  The installation program

 will determine which type of computer you are using,  either Windows or macOS,

and install the appropriate routines.  Follow the instructions in the program. 

You may delete the InstallHoku.jar file when it finishes.


On a Mac, if you get an error message that the InstallHoku cannot be opened,

“because it is from an unidentified developer”, then right-click on InstallHoku,

and select “Open With” and choose the JavaLauncher.  You will be asked to confirm

that you do want to open this file.


If you get an error message that you cannot run the InstallHoku.jar file, then

you may not have Java installed on your computer.  See Installing Java below.


New Features in version 1.9.3


You can now create multiple Desktops, one for each project.  A History module lets you extract the jobs that created an image.  You can name your crop windows to better keep track of them.


Upgrading your Hoku version


In the future, to upgrade Hoku, when a new version is released, download the new InstallHoku.jar, and double-click to install the new version.  Your existing data, on your Hoku Shelf and Hoku Desktop will not be changed.  All of your existing data will be available to you in the new version of Hoku.




Although they were created for an early version of Hoku, a series of introductory videos is available:


Multispectral Image Processing (37 min.)

Getting Started – Macintosh (14 min.)

Getting Started – Windows (14 min.)

Creating a Job on Hoku (36 min.)

Extended Features of Hoku (1 hr. 5 min.)

Background Suppression (35 min.)




You may contact the author at the email address below if you have questions,

need help on a specific problem, run into problems, or have comments or suggestions.




    Copyright (C) 2021,2022  Keith T. Knox


    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; version 2 of the License.


    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of


    GNU General Public License for more details.


    You can read the GNU General Public License in LICENSE.txt.

    You may also obtain a copy of the license by writing to the

    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    Boston, MA 02110-1301 USA.


                                                  Keith Knox


                                                  5 December 2022


Updated: 5 December 2022