NAME

Tablet - a digitizing tablet simulator allowing two-dimensional coordinates to be digitized and saved to a file from transparencies or digital images

SYNOPSIS

The method for executing this program varies according to how a particular platform supports the execution of stand-alone Java programs. In a command-line environment, java -jar Tablet.jar will work when the jar file is located in the current folder. If the jar has been unpacked, use java com.angelfire.bobwb.tablet.Tablet in the folder where the jar file was unpacked. You may need to install the Java Development Kit (JDK 1.2 or greater) or at least the Java Runtime Environment (JRE 1.2 or greater) for Java code to be executable. There are no command-line arguments.

DESCRIPTION

A digitizing tablet provides a way to move vector data from a picture to the computer. In the absence of such a facility you can use this Tablet program.

Your picture must be copied onto a transparency or scanned into a image file in a Java-supported format. If you are using a scanned image, use the "Load Image" item of the "File" menu to display the image on Tablet's digitizing surface.

If you are using a transparency, you must first tape the transparency over the computer screen so it is centered and rectangularly aligned. When the window of Tablet appears, resize and reposition it so that the digitizing area (the large blank sub-window) contains all the contents of the transparency you are interested in marking.

To begin digitizing, put your attention on an area with a group of locations you want to mark. If you would like to label this group in the point file, use the "Insert Label" item in the "Edit" menu. Supply a label when prompted. Begin selecting locations by pressing the left mouse button with the mouse cursor over a location of interest. As you move along selecting this and further locations, x's will mark the locations you have selected.

At any time, you can select "Insert Label" to put another label in the point file. This label will appear in the point file after the points already selected and before any new ones which you select. When you are through digitizing altogether, select the "Save Points" item from the "File" menu to save the point and label data to a file of your choosing.

At any time, you can change the color of the markers by using the "Color" item of the "Options" menu. This may be useful when the current marker color wouldn't be readily visible in the location you wish to select. Color values are not saved with the point data. The color starts out as black, and the color will revert to black whenever the points are cleared or a new image is loaded.

At any time, you can specify reference point values which will be used to offset and scale the points you digitize. For this option to be useful, you should have coordinate values in mind for at least two points on the digitizing surface. Choose "Set References" from the "Options" menu to put the tablet in the mode for specifying reference points. Select a reference point by pressing the left mouse button at the first point with known coordinates. A dialog will pop up requesting you to specify the floating-point coordinate values you wish to correspond to that position. Type in the X and Y values with a space between them and no other punctuation. (Exponential format is not accepted, but you can pad with lots of zeros if necessary.) Repeat this for a second reference point.

When the Tablet is in "Set References" mode, all the menu options remain available. The "Undo" facility can be used to re-specify the reference points, to escape from the mode altogether or to re-enter the mode. You will not be able to digitize points until you exit the "Set References" mode either by completely specifying the two reference points or by completely escaping from the mode using "Undo". Once two reference points have been successfully specified, the Tablet will echo your position in exponential format according to the scale and offset specified by the references.

If you are digitizing from a transparency, the "Set Size" option from the "Options" menu can be useful if the transparency is larger than your computer screen. This sets the size of the digitizing surface in pixel coordinates. When prompted, enter integer values for the width and height separated by space and without punctuation. You will have to move the transparency to coordinate with scrolling.

There are a variety of choices in the "Options" menu to manipulate the grid. "Grid Off" (or "Grid On" when the grid is off) toggles the display of the grid. "Grid Spacing" allows the setting of the spacing of the grid tick marks in pixel values: type the integer values of the desired width and height of the spacing with no punctuation when prompted. "Grid Origin" allows the origin of the grid to be changed: click the mouse at the desired origin. This process can be escaped using the "Undo" facility in the "Edit" menu. The color of the grid can be changed by turning off the display using "Grid Off", changing the color using the "Color" item of the "Options" menu, and then turning the grid back on using "Grid On".

An "Undo" facility is provided in the "Edit" menu. Inserted labels and color selections are undone silently.

Robert Burkhardt Software Services, P.O. Box 426164, Cambridge, MA 02142-0021. Previous versions of the program were written using the X Toolkit and the Graphical Kernel System (GKS).

COPYING

Copyright 1999-2006 Robert Burkhardt

This program is free software; you can redistribute it and/or modify it under the terms Version 2 of the GNU General Public License as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. You can also find a copy at the Free Software Foundation's website.

BUGS

None currently outstanding. The application is currently in beta since the recently implemented scaling facility has not been thoroughly tested. Please send any bug reports to R. Burkhardt, P.O. Box 426164, Cambridge, MA 02142-0021 or bobwb@juno.com.