At the present time, the following imagery, all TM, is stored in a Directory called "PITimages". This contains the following scenes: 1) Morro Bay, the same image as used in Section 1 of the Tutorial; 2) Rocks, the same Waterpocket Fold TM scene used in Section 2; 3) Israel; and 4) Bloom, the TM scene arounds Bloomsburg, PA used in the Final Exam. Each image is 512 by 512 pixels (about 16 km or 10 miles on a side). For this training session, we will use the Israel scene, which is dominated by agriculture, with several types of crops and fields free of growing produce, along with towns, sand, and water. The scene is along the southern Israeli coast, with the town of Ashdod on the coastline. The image was acquired in August of 1985. To begin, follow these next steps to learn ways to call images into the Thumbnail window. Then, work through the subsequent instructions.

NOW, TO GET STARTED:

1. As always, you start by loading the program, using the icon.
2. A big black window, with "No Image" in its center, and labelled PIT on its title (top) bar, also contains the main menus accessed through 6 buttons on the left and a Help button on the right. This black window is called the "Thumbnail" window (a throwback term to earlier versions of PIT in which it, and several others, were notably smaller). You will use this window to display individual gray scale images or color composites.

3. For some reason, the HELP button and About Help don't work in the version you have downloaded. Sorry!
4. Next, simply click on each of the left six buttons to familiarize yourself with the various command options. Some are in black, and ready to use, others in gray will only be later activated (into black) when a particular program or stage in processing is running. Be advised that clicking on the rightmost button "Windows" presents an error message - ignore this and click out. But this button starts to work as soon as you have loaded an image into the large window.

You're ready to start actual "hands-on" tasks with images.

5. Click on the Images button, then Open, and the window labeled "Enter Image path, sources, and size" comes up. Note that on the right are seven "Browse" buttons each associated with a rectangular box labeled Band 1, Band 2,....Band 7. Click on the first Browse button (Browse function as an Enter button).

6. A window labeled "Select band 1 path " appears, containing a smaller window with a long list of files beginning with the file "PIT images".
   
   Ignore the README first listing (this illustration is out of date). You can click on the Parent Directory button - it may put you out of PIT and into other directories on your computer (this also holds for the Absolute and Relatuve Directories. (Note: the Cancel button here works to bring you back to the previous Window; but don't click on the upper right X button as this puts you out of PIT.) In the right subwindow are a list of directories and files. Don't click on any of these; if you do the wrong final directory will appear. From the list you should now double click on PITimages and a list of 4 sets of TM images will appear. Ignore the NB group of files as these have now been removed from those available to you.
7. First listings are the 7 TM bands labeled as ISRAEL. This scene covers an area including the town of Ashdod, about 20 miles south of Tel Aviv, a nearby military airport, and crop fields. Highlight (in blue) ISRAEL.1 by single clicking on it and click on Open (syn.: Enter). Note that the rectangular box labeled band 1 is now filled with ./../PITimages.ISRAEL.1.
8. Move to the second browse button and repeat the previous procedure which inserts ISRAEL.2. Do the same now - browse button-highlight name-open - for those other bands as you wish to enter - in this case, all 7 TM bands for ISRAEL, which will be the image scene we will work on first in Appendix B. Be especially watchful in this sequence and make sure that the band number you want goes into its corresponding box; for TM you will confuse things if you put, say, TM 3 into Band 1 - it's good practice to have TM and band numbers the same; if you make a mistake and put the wrong band into a box, simply hit Browse and choose the correct one - this will overwrite the erroneous one. You should have a display like this except that you will have ISRAEL instead of EOSAT/MoroBay# as the entry (I decided to have you work on a scene totally new to you rather than on one already used in the Tutorial [which you can work with later at the end of the Cookbook routine]).
   

9. Go now to the Source Box and press its Browse button. A listing of Landsat sensor systems,NOAA/AVHRR, and GOES sensors will be shown. Highlight (blue) Landsat TM; then enter via the Select button.

Move to the next box (not shown), Size, through its Browse and pick the only choice, 512 x 512 and hit its Browse button. (Note: you must fill both the Source and Size boxes, otherwise, when you try to Open you will get a no image selected message.)
10. Now, click on the Open button at the bottom. If you have not placed entries in all 7 available band boxes, a window will replace the band entry window telling you that certain bands were not specified, and you will be asked to acknowledge this omission. After hitting Acknowledge, a large gray tone image will appear. This is the initial Thumbnail for the scene, a view of TM Band 1. Take a quick look; locate the following reference features: Mediterranean sea; docks; town of Ashdod; sand dunes; roadways; airport; active crops (darker rectangles, etc.); fallow fields (medium gray patterns).
11. The Image routine serves just to get the different bands online. Only one image, by default the first band, is automatically displayed. Clicking on View-->Current confirms that B1 is being displayed. You may wish to drag (on the blue banner at the top) an image to the right, as this may remove it from a screen that defaults to the left.
12. To see the other bands, and do some image adjustments, you must click on the View button. Then choose "Display Image Control Window". The first thing that appears is a small window labeled: PIT - Thumbnail Image Controls. It will have three rectangular boxes, the first (top) is labeled Expression, in which B1 is entered, and the second and third, each with a sliding button, labeled Contrast and Brightness. At the bottom are four larger buttons, two of which, Apply and RGB, are of interest at this time.
13. Our first task is to examine each of the 7 bands. To see B2, you can proceed either by placing your cursor in the Expression box next to the 1 and delete that character with the left keyboard arrow, then type in 2 in its place and click on Apply. OR it may be easier for you to click on the black inverted triangle button to the right, which will drop down a list from B1 to B7, then clicking on B2 (or any other) and Apply. Each of the other bands is called up in the same way; but it replaces the previous band image which is lost (a way to save and display two is described later). Familiarize yourself with the appearance of each band; Band 6 is the thermal band and is rather washed out in this unstretched rendition. Look at it.
14. Unfortunately, this initial version of PIT does not automatically label each image by its name. To check the band number being displayed, drag the Thumbnail Control box to the right and on the image window click View, then Current, as you did for B1 earlier.
15. The appearance of some - maybe all - of the bands can be improved. The standard way is through some type of contrast stretch. In Section 1 on Morro Bay some of the mathematic stretches were defined and explained. PIT, as now developed, does not have these capabilities and flexibilities. To contrast stretch, PIT simply permits two manipulations but these lead to meaningful and esthetic results. You will use sliding Brightness and Contrast buttons as described next. To see these buttons, click on View, then Display Image Control Window, which brings up this display:
    

16. To learn the effective use of these sliding buttons, go back to any of the bands you wish. Let us choose Band 4 (B4). Get it displayed. Now move (holding the left mouse button down, displace the sliding button by dragging the mouse on its pad) the sliding button for Contrast all the way to the right. In the small window next to the button, a number "*8.00" should appear and the image becomes bright white after clicking Apply. Then, drag the button all the way to the left and look for "/8.00"; the image is dark (black) after clicking Apply. Once again, bring the button back to its center position. Now slide it slowly to the right. At some short distance, the number "*1.10 will suddenly appear. So, keep dragging it rightward and note that the numbers increase by units of 0.1 (leftward, the same result). Same holds for slow leftward movement. Trying the same approach using the sliding Brightness button produces a right range up to +400 and a left range to -400. Slow movement from center starts right or left increments in units of +10 and -10.
17. Let us do a sample stretch. Set the Contrast button at *1.50 and Brightness at +100 and then click on Apply. You will note an overall change in image gray tones, with a somewhat different range of gray levels and an overall increase in brightness. The resulting image may strike you as improved from the start - this is a rather subjective judgment. Now set the C and B limits at *250 and +200. No doubt you will react negatively to the result. Try C and B limits at /150 and - 200. This also will not be a pleasing result. For a given image, there tends to be a narrow range of C and B in combination with changed values that give satisfying improvements. You, as the analyst must pass judgment on a set of B and C values that seems to you to improve image quality - but this is obviously subjective. Note: if you move the buttons left or right only slight amounts (before any numbers appear) and then hit Apply to see any changes, nothing does change and the buttons revert to center; this means that real changes can occur only when numbers start appearing. Generally, most images improve when the C numbers fall in ranges less than *2 and /2 and B not greater than + or - 150 but some processing operations yield new images that require more extensive stretches or overall tone increase/decrease, so that the larger values apply. While you are at it, try to find the best stretch that optimizes band 6 gray levels.
18. Images in color are the next set of products sought through image processing. PIT makes these in a straightforward way. To start, again click on View and then Display Image Control Window. As before, the Thumbnail Image Control window will come up, as it does for individual band stretches. But, now click on the RGB button, and a new larger window comes up with three internal rectangular boxes, the top outlined in red, the middle in green, and the bottom in blue.
    
    Each one also has a pair of C and B sliding buttons. Note that, by default, B1 (but B2 in the above illustration) is inserted in each of the three Expression boxes. Also, there are Gray and Palette buttons to the right. Do not use the Palette button at this time. If you want to see any individual band image, press on Gray which will bring up any individual band you enter in the usual way. A stretch may be needed. Now, this is important: You can change the band you want to see with a given color simply by placing the mouse cursor in the band box, slide the cursor until it is next to the number, then hit your backspace key, removing the number, and then typing in the number for the band you want (alternately, move the cursor to the left of the number, then hit delete).
19. To see an image in color, choose what band you wish to render in the particular color you select, either by accepting what is already entered or changing the band number in the Expression box or clicking on the black triangle (which has a vertical list of the bands you selected and selecting the Band desired). As an example, put B4 in the red Expression box, B3 in green, and B2 in blue. Then press Apply. A standard false color composite, with vegetation in red, should replace the band 3 image. Next, either delete/type the number or use the triangle, put B3, B2, and B1 in the red, green and blue outlined boxes. This will give a natural color view.
20. But, better renditions are possible, even likely. Move experimentally the sliding Brightness and Contrast buttons for each of the three bands to new positions, followed by Apply. Keep doing this until you reach a color display that seems close to nature or is at least esthetic.In effect, you are enhancing the image by selective, band by band, contrast stretching.
21. For the fun and knowledge of it, try other combinations, as you choose. For example, R = B7, G = B2, B = B4. Various subtle new information may emerge from some particular combination. Also, vary C and B. Remember to enter through Apply.
22. PIT has a systematic size changing program, or Zoom, that enlarges or diminishes an image. To bring about a change, follow this sequence (which also previews a major operation which we will do under the Classification tutorial): From the PIT Thumbnail window (hereafter, alternately just referred to as the PIT window), click on the rightmost button, Windows, then through these choices in the step windows that will appear to the right = Open - Interpretation - Scheme (top or left; choose either). After the left mouse button is released at the last step, a large window will appear with a black rectangle on the left (or top; depending on choice) and an image will appear in a window to its right. That image is the current one that is active. If you prefer to display another band, press on View, click on Display Image Control Window, then change band number in the Expression box (or click on RGC and fill in all three to get a color composite), and hit Apply. Note that the image that you settle on will have a square grid superposed on it (this grid is used in the classification procedure but appears here so that you can move the cursor into any grid square and that will be the image area centered in the enlargement). If you wish to remove this grid for now, go to View, then click on Show and note that four options are listed. One is labeled Grid and has a check mark in front. Click on the check mark, which removes it, and then displays the image without the grid. You are now ready to Zoom.
23. Either with or without the grid displayed, the procedure to change size is straightforward. Assuming you are still in the PIT-Interpretation window, first, click on View, then on Zoom in its dropdown menu. This will display numbers like 2x, 4x, 8x, ... . Whichever has the check in front denotes the size increment that will take place one step at a time. Most instances, an increase by 2x is adequate, but the higher numbers enlarge or diminish the image by greater amounts. For now, choose 2x. Then, click on Mode (top left button), and in its window menu will be two options: Zoom In (enlarges) and Zoom Out (diminishes). Assuming you have a full scene in display, choose the Zoom In command. Nothing apparently happens but move your mouse to bring the cursor into the image. You should see that the cursor has changed to a small bright square outline with a dot in its middle. Place that square somewhere in the image where you seek enlargement and click once (left). A new scene shows up in the image window, which you should recognize as a part of the image surrounding the square at its center. If you want to see a different area enlarged, repeat the procedure with the cursor placed within it. Or, given the first enlargement, center the square and click again. Once more, the expansion is by a factor of 2x; the image now begins to show individual pixels (as squares) but recognizable features may still retain identifying patterns. Repeating this once more (now 2x three times, or 8x) makes the pixels so large that the patterns begin to break down. To reverse the size increase, go to Mode, then Zoom Out, placing a check mark there, and then clicking on that command. The resulting cursor, when it is placed somewhere on the (usually enlarged) image, has a different shape: it is a cross (+) with the tips ending in tiny arrowheads. Depending on the degree of enlargement, one or more clicks will in effect increase the displayed pixel size while restoring the image scene to larger scene areas that are displayed. From 8x, three clicks will restore the original full scene, if that was the starting point. Enlargements by zooming in provide smaller subsections of a scene that may be all you will wish to classify or otherwise manipulate. Note: you can start with a higher zoom factor, e.g., 4x or 8x, cutting out incremental steps.
24. PIT presently is not designed to routinely display more than one image band at a time in a simple, convenient fashion but there are two ways to compare bands. The first is just to put up any starting image in the usual way (when I use the term LOOK after this, it will refer to this way), namely go to View - Display Image Control Window and type in the number on the top for the band wanted, then hit Apply. The band is displayed. To look at any other band, just overwrite the band number, e.g., if the first display is B1, then replace the 1 with, say, 3. The new band comes up, but the first band is lost. What you would like to do is keep the first band and then display any other band and compare them side by side. To do this, first put up the PIT Thumbnail image you want in the usual way, such as you did at the start. Then, go to the Windows button on the right and follow this sequence: Windows --> Open --> Classification -->Supervised --> Partial --> Top Scheme and click. A second large screen will appear; drag it away from the first. It is labeled PIT on top; the first screen display has become PIT-Interpretation. If necessary, make this second screen your active one (top banner needs to be blue). Now do a LOOK (remember: View --> Display Control Window). You get the Brightness and Contrast buttons. Just overwrite the B1 on top with B4 (replace 4 only) and hit Apply. Band 4 comes up; change B & C as desired. You can move one or both images to better positions by dragging on their top banners. Now you can compare side by side; both images together may be large enough at the screen setting used so they overlap, but varying their positions should bring corresponding parts into view. Here's another trick. Go to the first image (you can verify what band it is by going View --> Current), and do a LOOK on it, and replacing its band number with any other you wish to compare. In fact, you can repeat these LOOK adjustments to get any two of the bands you loaded at the start. This procedure is cumbersome, but it works.

To leave PIT altogether, go to the PIT button (first on left) and click on Quit. But, you may wish to leave one image data set and look at another. You can just quit and start again. But there is an alternative. Go to the second button, Image, and click on Open. You will see the band(s) you already have worked with. Go to the first Browse button and proceed (through 3 menus) to PIT Images and find the first band from the image you now want displayed. Click on it and insert - it will overwrite the previous image. Do that for other bands; if you wish to skip one, just "erase" it by sweeping with your cursor over its entry and press delete. Now press Open and a Save Current Image box drops down. Click on Cancel and a box will appear that may inform you that one or more bands were not chosen - in this case hit Acknowledge and the new image(s) will be loaded, with the top one displayed (if you hit Cancel, you will be bounced completely from PIT). This example illustrates that PIT has limited flexibility in moving around from images displayed and processing routines; you may be shoved off the program if the wrong command or option is given, but with experience that will decrease in frequency.