Image initially displays the top slice (or plane) of a database. To change which slice it displays, link in a slider. It will usually be able to track the slider's changes in real or near real time.
Image also behaves as a Data Object; note the drag and drop icon at the right of the second row of buttons. That means it can be used to feed data into other applications. Image doesn't change the data, however, so the only effect it has on data "passing through" it is to select a single slice. All data it supplies, therefore is two dimensional. This can be useful if one wants to do many operations on just a single slice. If, however, a bounding box is active (and on the screen), then Image will only output the area within the bounding box.
The Histogram button starts a histogram application that is automatically linked to the Image.
The RGB button drastically affects how Image displays its data. When RGB mode is turned on (by pressing the button), three slices are displayed simultaneously. One slice is displayed in monochrome red, one in green, and one in blue. Use an RGBSlider or LinePlot to choose three different slices for this mode. If all three slices are the same one, then RGB mode just turns the image monochrome grey. That's probably not what you want.
The Image button starts another image application. If there is a bounding box active, only the points inside the bounding box will be displayed in the new Image.
The Line Plot button brings up a LinePlot that is automatically linked to the Image.
The Freeze button, when pressed, prevents the Image from being
updated by its data object should the latter change. This is useful for
producing a thumbnail image.
Crosshair puts the application into "Crosshair mode," allowing you to control the crosshair. It starts in this mode; it is only necessary to do this if one was using the bounding box. See the Crosshair section below for more information about the crosshair.
Selecting Bounding Box puts the application into "Bounding Box mode," and allows one to change the size, shape, or position of the bounding box. See the Bounding Box discussion for more about bounding boxes.
Profile Line allows the drawing of a line on the image. The menu sub selections are Draw and Remove corresponding to enabling or disabling the line drawing feature. If Image is linked to Profile, Profile will draw a graph of the data along that line.
The Grid entry controls the features of any grid to be drawn. The menu includes three grid settings; "No Grid" obviously turns off the grid---that's the default. "Fine Grid" draws a grid aligned with the small tick marks in each direction. "Course Grid" draws one aligned with only the big ticks in each direction. In "Fine Grid" mode, the big divisions are highlighted. The "No Data No Grid" toggle only applies to projected images. See below for more information.
Expand Colors temporarily changes the color palette used to display the image. If this option is checked, the palette covers only the range of data values in the current slice. If not, the colors are normal, and the palette covers all the data values in the whole database.
The Smooth Magnify button enables a smoothing operation to be performed when magnifying an image. Normally, the magnify button enlarges images by pixel replication. That means that every spot in the image represents real data. It can be a bit blocky, so to smooth out magnified images (and grid overlays, if present), turn on Smooth Magnify from the menu. Note that this feature does not work well in RGB mode.
The Overlay menu allows the addition of overlay graphics onto the image drawn. If an overlay is selected, it will be drawn; re-selecting it removes it. For more information, see overlays. The coast overlay maps coastline onto the image for the case where longitudes range from 0 to 359. If longitudes range from -180 to 180, use coast180.
Bounding boxes can be inclusive or exclusive. Inclusive bounding boxes represent all the data within the edges of the box; exclusive ones represent all the data outside the edges of the box. The edges of the box are included in each case.
ValueView will indicate which values are within Image's bounding box if Image is linked into it.
Image can be used as a magnifying browser by doing the following: load a big database into Image. Minify it a bunch of times until it's a convenient size. Draw a bounding box. Hit the Image button. Move the bounding box, and a magnified version of the contents of the bounding box will be displayed in the second version of Image.