An Introduction to the Concept of Imaging in Education
But before you jump into my Readers Digest condensed version of an Introduction to the Concept of Imaging in Education, please, go get the free software, pick up the lesson images, lesson plans, Primer for the Teacher and student handouts. Well OK, to heck with the lessons go get the software and an image or two. Grab the small images of the Great Red Spot on Jupiter (60kb) if you're really short of time. And I will see you when you get back. But in any case, please do play with the stuff.
Who of us involved in teaching has not struggled to make difficult concepts simple and easy to understand. And who, involved in this struggle has not turned time and again to visualizing information as an obvious solution: a solution that offers a way to see the unseen. And this seeing the unseen is a fundamental tenet of Imaging in education.
The comical retort... "Do I need to draw you a picture?" is an appropriate example of a natural tendency of our species to be primarily visual. We start in Kindergarten with the daily calendar. Day, date and brown leaves for October. Hey, it works, so we do it.
The Primary grades are full of visual information conveyances. Big books, flash cards, the multiplication tables and clocks; singing, dancing, tying your shoe blocks and throw the ball junior. In the middle school years, the skeleton in the lab closet, the Mercator effect, atoms (when will it be Gluons?), stars, planets, cell models and Newton's law. It is no secret to great teaching that to see an object does wonders for the transfer of ideas.
At this point I have established that the concept of visualizing information is not new to you. This is the point I want to hammer home: visualizing information is a normal way for the species to go about the business of discovery. Imaging in Education, the subject I am introducing, simply adds to the mix, the capabilities of the computer to manipulate images in the service of understanding.
As fascinated as I am with how things work, I am going to give you the condensed version of the fundamentals of Image Processing in Education. If you are inclined to this same fascination, check out the following book list .
Computers only see what they see digitally. And images, digital images are no more then a string of numbers. Those numbers control what the computer displays on your screen. The computer shoots electrons at the back of the screen. Painted on the back of the screen is several "colors" of phosphor. The phosphor gets excited by the electrons and in the excitement becomes luminous. If it is a red phosphor it glows red, green glows green and I will let you guess what blue phosphor glows! Through various ways these three dots of color together can be seen as any one of 256 colors. Each dot has a fancy computer name. These dots are forever more (at least in this document) called Pixels. Stands for Picture Element if you have to ask. Enough with the techie information, on with the show.
Let me introduce you to a piece of free software (freeware) that works on the Apple Macintosh computer. This free program is called NIH Image. And it does one job brilliantly. Its mission in life is to help humans analyze pixels. One pixel at a time, a group of 9 or an array of 300,000 thousand. It slices, it dices, it can graph, plot, measure, create data sets (which you can export to your favorite spreadsheet for graphing, by the way). NIH Image can magnify the image, edit, enhance, apply a new coat of colors and teach an old dog new tricks.
In fact the guys and gals who invented and maintain the software at the National Institute of Health (NIH) (now you know...some...of the rest of the story) take no less then 3 pages describing the glorious capabilities of NIH Image.
In this venue I will introduce you to about 9 of these tools for image analysis. They are:
And for advanced users there is the opportunity to work with density profiles and surface plots, both tools that are "too cool for school" according to my students.
Beautiful pictures (eg,GIF,JPEG, PICT) versus images with
Scientific merit for study and analysis (eg, TIFF, PDS, FITS):
To corrupt an image is to change the original image pixel. This change
is actually seen in mini lesson 1c.
Corrupting the pixel value might happen because a photographer wants to make the image size smaller. This is done because a smaller image file is easier to use and can be sent quickly to friends and associates. And it looks just as good to the human eye as the original bigger file. Maybe better? So no harm is done if the photographer is interested in sharing the pictures beauty. It is still beautiful. But it no longer can be analyzed for pixel values that have scientific meaning.
One of the first techniques that was used to move images around the
Internet was designed to make the picture as small as possible. That technique
added three letters to each image file so people would recognize a picture
file from a text file. Those three letters are "GIF" which means Graphical
Information Format (I think). This file shrinking technique works great
for maintaining the beauty of a picture while making the file as small
as possible. But all gif files have corrupted/changed pixel values. Can
you guess what the standard file formats for images on the world wide
web is? Yes, GIFs, and another great file shrinker called JPEG, are the
image files of choice. Smaller files transfer from one computer to another
more quickly. And this is preferred on the net. If you doubt this go get
the 1.8 meg (1,800Kb) 24 bit TIFF image of Jupiter. It is called jupiterWS.tif
I'll bet you dimes to dollars the time it takes to download the image
will try your patience (unless your name is Job).
OK, OK! For all the tech heads, if a technique to shrink and un-shrink images corrupts the image, it is known as "LOSSY" ( information is lost). If it does not corrupt the image when it shrinks it is "LOSSLESS" (no information is lost).
The Image Processing for Teachers project has some great free sample lessons. The one most germane to Live From Hubble Space Telescope is a lesson you can get that lets the kids image process the Moon IO and its spectacular Volcanoes.
Bringing Image analysis, digital video and the net to the class.
Index of Images used in Lesson.
Introduction to Electronic Field Trips