History
    DataCapture was born out of frustration, and after much procrastination. Every time I had to get numerical values of a graph from a journal or a conference paper, I had to painstakingly approximate data points from the graph as best I could. Every time the points would come out inaccurate and a rather poor reproduction of the actual data. I wanted to write a program that would automate this task, and do a much better job at that. But then, that was three years ago.
    Finally its done. Its not the best thing that I have created, but certainly, one of the most useful (atleast as far as I am concerned.)

Download
    The program is written in Tcl/Tk. The source code may be downloaded here. Image [File 1] may be used for a quick test*.

Documentation/Installation
Installation
    1. Download the file from here
    2. Make sure that the file has executable permissions. (chmod 755 <filename>)
    3. Find out where your 'wish' interpreter is located. (which wish)
    4. Execute the program from a terminal. (Remember that the output is going to be writen in the terminal).
    5. Enjoy!

Documentation
    Using/Hacking the program is very simple and intuitive. These are the steps you follow to execure the program.
    1. Execute the program from a terminal.
    2. Click on the 'Open Data File' button, which lets you open a .gif image.
    3. Click on the 'x-left' radio-button, and then click on a point (towards the left) on the x-axis whos value you know.  Type this value into the entry-widget on the immediate left of this radio-button and press enter. A red circle appears on te graph, denoting the position that has been selected.
    4. Repeat this for 'x-right', 'y-top' and 'y-bottom'. These tell the program the pixels within the image that correspond to specific points on the axes. Remember, if you mess up here, the results are going to be messed up too.
    5. Click of the 'data point' radio-button and then start clicking on the data points within the graph. A green circle denotes the position of the data point that has been selected.
    6. After all the necesary data has been demarcated, click on the 'convert data' button. At this you will be able to see the necessare data on the terminal in which the program has been executed.

Tips and Tricks
     1. Remember output redirection ! This always saves you the trouble of manually copying and pasting the data.
     2. You might want to take a look at ImageMagic for converting images from one file type  to another. Remember that this program can only take .gif input files.

Expectatios
     1. At present, the program only expects .gif images. You might consider using ImageMagic to convert files. This is because the canvas widget of even the latest release of Tk/Tcl supports .gif files only. Other people  have provided ports for displaying other types of images, but its always better to have a simple program that works everywhere rather than the massively complicated program that does not work most of the time.
   
    2. At present the program expects that the graph axes are straight, alligned horizontally and vertically. This is a condition that is generally true for copies of journal/conferecne articles that have been downloaded from IEEE Xplore of similar sources. Scanned/photocopied articles are much more difficult to get right. I would possibly rectify this issue at a later release of the program.

News
First Release:
                        Version 0.1
                        Sunday 06, Februaru 2005.

Screenshot

Click on the thumbnail to get a bigger picture*.

License
This is free (as in freedom) software. It is distributed under the GNU Public License (GPL). Go ahead and hack the code as much as you want. Remember that this program comes with absolutely no warrenties.

Author

Sankha Subhra Mukherjee
Semiconductor Device Research Laboratory
Rochester Institute of Technology
Rochester, NY - 14623.

Sankha.Mukherjee@gmail.com

* (The images in this page are hosted by http://www.imageshack.com).