Welcome to Geomove

You may move, stretch, rescale, and precisely georeference images and shapefiles, individually or in groups all together. You may also rotate, move, stretch, rescale shapefiles or just selected features in them. Images cannot be rotated. You may do this on screen with your mouse or through data entry in a dialog box. It is all very simple to use.

This example is from an ArcView 'view' document consisting of multiple images and shapefiles. Note that there are copies of shapefiles simply stretched and/or rotated for effect. But some tricks are evident. A key map for example is easily made from a copy of a shapefile then reduced in size and moved into place. Images can be stitched together by simply mouse moving one corner to match another then mouse stretching the other to match the opposite corner. Pictures in pictures can be framed by interspersing polygon shapefile that are also sized to fit. Images and vectors can be located with the double coordinate precision you expect from a professional GIS, and done quickly and easily. To Geomove, images and shapefiles are just objects on the screen to manipulate at will.

Pull Down Tools on Tool Bar

XY Locate Tool

The first is the XY (point) Locate tool. Select all, some, or only one image or feature theme. Pick the tool and go to the View. You will see a bulls-eye cursor on the map. To adjust for a precise location, move the cursor to where you wish to enter an exact value and click to set a point. A screen containing the location of your button choice will pop-up. It will be in either Cartesian coordinates (UTM etc.) or in Degrees/Minutes/Seconds depending on how an image was called up to begin with. You may now enter an edited value or values that are actually known at that point. The theme will be repositioned to reflect the change.

Drag

The next tool is the Drag or Move tool. Select all, some, or only one image or feature theme. Locate the first point by positioning and holding the left mouse button down and drag the bulls-eye cursor to the place where you want to move the image(s) (or that particular point on the images). Release the button and the images selected will be relocated to reflect the change. You may fix the movement along the x or y axis using the Shift or CTRL keys. The cursor line remains 'free' but movement is restricted. Thus; SHIFT+mouse Drags x direction only. CTRL+mouse Drags y direction only.

Horizontal Stretch and Vertical Stretch

The third and fourth icons are the Horizontal and Vertical Stretch tools. This allows you to change the baseline dimensions. Point and drag the mouse from one place to another, to either expand or contract the image. The horizontal base line will be adjusted, as will the vertical scale.The 'Horizontal Stretch' and 'Vertical Stretch' tools operate on all active images or feature themes, and stretching occurs rightward from the leftmost or downward from the topmost edges, or 'pinned' point of the selected images. Stretching is rubber sheet like. The 'Set Reference' function resets this location, eg, pins the rubber sheet centre.

Stretching is proportional to the baseline and is a function of the location on the map where the stretch line is drawn. Stretching functions as if the map is a 'rubber sheet' pulled away or relaxed toward the reference edge, ie the leftmost or topmost edges. For example, a small stretch line drawn close to the reference edge will cause the whole of the selected images to be stretched as if the farthest edge has been pulled to accommodate this small change. This results in a large baseline change. A similar stretch close to a point farthest away from the reference edges will produce a small change. This allows for direct visual pixel matching on the screen or pixel pulling to a plotted point. The aspect ratio is not changed.

Bi-Directional Stretch

This tool allows you to stretch all active images or feature themes in the direction of the mouse drag. The aspect ratio option must be in the free mode. To set the aspect ratio to 'unlocked' go to the pull-down menu (GeoRef) and click on 'Unlock Aspect'. If the menu item reads 'Lock Aspect', the aspect ratio is already free, and the tool can be used.

The aspect ratio of the images are normally locked to prevent accidental distortion. If you have skewed them and wish to return to the original, simply reload them. This writes a new World File. To preserve aspect ratio adjustments, load the image via the ArcView 'Add Themes' function. This cannot rewrite the World File. If the cursor crosses a reference edge, the baseline calculated may result in a negative or very large value and an error message will appear to tell you that. The reference can be reset using the 'Set Reference' function.

You may fix the x or y axis and aspect ratio as you stretch as follows. SHIFT+mouse To stretch in x direction only. CTRL+mouse To stretch in y direction only. ALT+SHIFT+mouse To stretch in x direction only maintaining current aspect ratio. ALT+CTRL+mouse To stretch in y direction only maintaining current aspect ratio.

Tools on Button Bar

Load & Georeference Image

These call for an Image Theme in the normal ArcView way. A pop up selection menu will appear. Next a warning dialog box appears if the image World File does not exist. You will need one to georeference. Thus, say 'yes' to accept, and it will be created for you. See below for more details.

Report & Plot (F11)

This locates a single point graphic drawn on the screen, and reports it's location, either in UTM/Local coordinates, or Lat/Long. If no Point is drawn or none selected, the location will show '0' in the coordinate dialog box. This is used for plotting new points from coordinate data.

Edit the point, entering a new value, (do nothing to accept the current value) and a new point will be plotted on the screen at the new location. Both points will show on the screen, with the new one selected. If the active graphic is a line or polyline, the report will advise it's length in both map and distance units, and the azimuth, and first angle. If the active graphic is a polygon, the report will advise it's area and perimeter in both map and distance units. The centroid is given in map units.

Tools on Menu Bar

Commit Any Preview to File & Cut Previews

When you rotate, move, or stretch shapefiles, you will not immediately overwrite the file. First you will see a graphics preview of the actions you asked for. If you are happy with the results then you commit. That is you 'Commit Any Preview to File' which writes the preview back to disk overwriting the original feature.

If you are not happy with your results then you 'Cut Previews' to start over.

Note that you may continue to use any of the move tools, but once a preview is on screen any subsequent actions are taken on the previews and not the originating features. The original features will continue to be on screen along with the previews until either cut or committed.

Rotate Feature Preview

Rotation of feature themes, graphics, and text is done with this function. Any number of active themes, active themes with selected features, active graphics, and active text can be rotated all at once. The first rotation produces a set of preview graphics. Further rotation then works on the preview graphics leaving the original features in place, until saved. Any active graphics tag along, but need only be selected the first time.The point of rotation can be chosen about:

- an active point graphic drawn on screen.

- center of extent rectangle.

Any graphic drawn, should have the set reference command run on it so that it is persistent throughout the rotation operations. When finished run the 'release reference' command to clear it. Run the 'Commit Any Preview to File' command to write the previews back to file.

Translate Theme Preview

Precise translation of image and feature themes together is performed with this function. The themes must be active. Translation can be relative or absolute, selectable in the dialog box. This operates like the rotation function above, except that you do not have a polyline translation option. Run 'Commit Any Preview to File' to write the previews back to file. This function is used to shift data either small amounts (eg 0.0001) or to precise locations outside the mouse drag accuracy.

Note that with both Translate and Rotate, you may operate on selected features, so that only a part of a file is moved. Thus, you may readjust selected features by rubber sheeting them to better fit a particular map.

2Pt. Registration

This function allows the registration of all active images or feature themes from two point graphics placed on the screen. A dialog box appears to indicate the current location of the graphic. You enter the new or desired coordinates, and the active images are automatically georeferenced and scaled to those new locations. See the example below.

The operation allows for the fixing or freeing of the aspect ratio. If the aspect ratio is fixed, then scaling is established on the X coordinate, while the Y coordinate remains in proportion to the current aspect ratio.

To operate, simply place two points on the active theme(s) at locations where the pixels (or some features) represent known coordinates. For accuracy you may zoom in and out to single pixels for each point. Make both points active ('handles' shown). Select this menu item, and enter the coordinates. The image(s) will be automatically located and scaled to the coordinates, and the point graphics will be deleted. In practice, you would place the first point in the upper left quadrant, and the second in the lower right quadrant, but that is not a mathematical requirement.

Set Reference

This function provides two types of coordinate graphics that fixes a chosen reference point for rubber sheeting and georeferencing.

If you plot or draw a single point graphic (and make active) at a location that you wish to pin during image rubber sheeting, an XY cross is drawn on the screen with a red dot showing which location is fixed.

If you plot or draw two point graphics (and make active), then a red rectangle is drawn on the screen with a red dot shown at one corner. This dot is the first point you placed and represents the fixed location.

Any operation involving Horizontal, Vertical, or Bi-Directional stretch will rubber sheet from the fixed point, that is, the red dot. Moreover, any stretch on the right of the dot will expand or contract the image relative to that point, and similarly any stretch to the left will do the same. For example, if you stretch the image away from the red dot with your mouse on it's right side, the left part of the image will stretch in the opposite direction, to the left. The red dot is the reference point on both the XY and rectangle graphics.

The rectangle allows you to do two point registration graphically on the screen. You may match an image to an AutoCAD drawing, to themes, or to plotted points very easily. First, zoom into a location that you wish to use as a fixed reference. This must be your first point. Zoom out. Zoom into the next location and draw a second point. Select the point (F8), go to the menu and click 'Set Reference'. A red rectangle is drawn with a red dot. Next, zoom into the red dot and pull the pixel you wish to match to the red dot using the 'Drag' tool. Then zoom into the second point, ie the opposite of the rectangle, and using any of the stretch tools, simply pull a pixel to the corner of the rectangle. The image is now georeferenced and scaled to both points, with the first one as the reference.

To remove the reference graphic run 'Release Reference', which toggles back and forth with 'Set Reference' as the reference is either on or off.

UTM/Local asks you for the UTM or local coordinates of the upper left hand corner and the baseline. Any units are valid, but UTM meters are preferred. OK accepts, Cancel exits. See the example below.

Lat/Long asks for the Latitude and Longitude of the upper left hand corner and the baseline in Meters. The dialog box lists the Degrees, Minutes, and Seconds of the location. OK accepts, Cancel exits.

Enter +/- SIGN to INDICATE QUADRANT.

Lat/Long 2Pt asks for the Latitude and Longitude of the upper left hand corner and the upper right-hand corner. The dialog box lists the Degrees, Minutes, and Seconds of the location. OK accepts, Cancel exits.

Enter +/- SIGN to INDICATE QUADRANT.

The corner location is the corner of the scanned image and may not always represent the actual location. In this case, enter the data anyway, and relocate using the XY tool

Lock/Unlock & Lock Aspect Ratio

Lock, Unlock and Lock Aspect Ratio will operate on all active Image Themes. They are used to prevent accidental repositioning or scaling of an image once it has been correctly set up. Use also for fixing a first reference while stitching together multiple images; ie position one, lock; position the second, lock; position third, lock etc. Lock/unlock is coded to the World File.

Clicking 'Lock Aspect Ratio' greys out 'Bi-Directional' stretch tool, and the menu item toggles to 'Unlock Aspect Ratio'. Click again to return.

To georeference an image you load it with the 'georeferencing' button shown above. For ArcView to position and scale an image on the screen it relies on a separate file called a World File. Click on this button and the following will pop up.

If no World File exists, then a dialog box will pop up advising you of that fact. Say 'Yes', and Geomove will automatically create one.

Geomove does not write or change the image file, only the World File, thus no harm is done if an error is made. Each time a tool is used, a new value is written to this file, and the image is refreshed.

Next, the following dialog box will appear if you choose UTM or local coordinates. Enter X and Y coordinates and a baseline (this is the actual distance on the ground as scaled from the photo).

Or this box will show if you choose Lat/Long, in which case you enter degrees minutes seconds keeping in mind your relative position from the prime meridian (negative values for North america).

Approximate values can be used to first call up an image, since other tools are available to accurately position and scale them later. However, these values are the ones entered into the World file, so if you have these then you can use them, but that is not a requirement. You need only to get the image to the general on-screen location at this stage.

Once the image is in the view, and roughly located, there are two methods that easily and precisely georeference it.

By known coordinates.

The most direct way is to give two locations in an image a set of coordinates. If you can visually identify these locations, you simply zoom into each area as closely as practical, and place a point graphic at each. Try to get the first point located in the upper left-hand quadrant, and the second in the lower right-hand area, forming opposite ends of a rectangle, if possible. Make them active (eg with 'handles'). Click GeoRef then '2Pt Registration'.

Enter the X and Y coordinates that you wish each of the points to become, and the image will change position and scale to suit these. If you had called up the image in Lat/Long, you would enter the Lat/Long values of each point. If you get them backwards, an error box telling you this will pop up.

By reference to features

This is just way too simple, all you do is mouse drag a pixel to a pin with the drag tool... then a second pixel to a corner with a stretch tool. Only two mouse moves! Here it is in detail.

Here you wish to move and stretch images in such a way that two image pixels match locations on some vector features, or to two points plotted with the eyeglass plotting tool. To tie an image to feature vectors, two point graphics must be drawn at these locations. These are points you wish to move the pixels to. You will also need to use the pull down 'Drag and Stretch' tools as shown above.

After you have drawn or plotted two points and made them active, run 'Set Reference' in the GeoRef menu. You will get a red rectangle with a point in the upper right corner. This point is the pin about which everything is stretched. This pin is a new coordinate origin. The World File is written to accommodate this new origin. Below is an example of four images, all active, and therefore working together that will be georeferenced as if they were one.

The pin and the opposite corner of this rectangle depict where the two points once were. Zoom into the pin area, (seen as A and B ), you should see the area around both A and B. Using the 'Drag' tool, and operating your mouse in 'drag and drop' fashion, pull the pixel to the pin, zoom closer, and pull the pixel closer.

Repeat if desired. Your objective is to drag the pixel A to match up with pin B.

When you are finished, zoom extents, but do not use the 'Drag' tool again, since the pixel and pin are now coincidental. If you drag the image again, it will move off the pin.

You want to match the rest of the image to the opposite corner, moving pixel C to corner D, or pixel C to edge E. One of the following tools will accomplish that.

The stretch tools rubber sheets the image proportionately from the pin, stretching and scaling on either side of the pin. The pin acts just as if you had pinned a rubber drawing to a board and pulled the sheet on all four sides to fit in proportion to the stretch.

The closer you are to the pin when you stretch, the greater the effect will be on the outer edges. It is better if you use the stretch tools nearer the lower right-hand edges, but this is not a mathematical requirement.

Click 'Release Reference'. The red rectangle and pin will disappear. Now all moving and stretching will occur around the upper left corner of the image. Run 'Lock Active' to prevent the 'Drag and Stretch' tools from working on the images, and to fix there location against accidental movement.

These operations will also work with feature themes together with images.

Since all move actions give rise to a graphics preview, and therefore do no harm to any file, you may try any of these tools on any set of shapefiles you wish. So try the following:

Make a few shapefiles active and use the drag tool to pull them over to the right then to the left. Then use the XY Stretch tool to stretch them to an fro. Then do the same with the other tools.

Then run 'Cut Previews'. Next make just one feature in one file selected, and repeat the above. Then draw a 'V' shape polyline and run the rotate.

It should be evident that you can now manipulate both vectors and images to you hearts content. Enjoy!

To digitize from images that are angled differently from vectors first find a common point of reference and rotate the vectors, or copies thereof, about this, digitize, then rotate back again about the same point. As long as the angle and rotation point are the same as your original rotation the rotate back operation will restore the vectors to the original position. Do not rotate around any of the theme 'extents' since these change the rotation point after each rotation.

Don't know if Geomove will do what you want? All you do is try it.

Want more tricks? Go to www.geokinetic.com