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- G.1 NCSA ImageTool
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- Glossary G.1
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- National Center for Supercomputing Applications
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- January 1991
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- January 1991
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- Glossary
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- Canvas
- A window where drawing operations may be performed.
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- Click
- An action performed on a mouse button by rapidly pressing and
- releasing it.
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- Color Look-up Table
- A listing of the set of colors currently used by the hardware to
- display color images. This table defines the mapping of color to
- pixel value. There is only one color look-up table, but its contents
- can change. This may also be referred to as a clut.
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- Color Palette or Palette
- A palette to retain a group of colors. Palettes are used to initialize
- the color look-up table. A palette for each image stores the colors to
- be used with the image.
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- Color Strip
- Values inserted into a file or displayed on the canvas that indicate
- the range of colors, with 0 at the extreme left and 255 at the extreme
- right. A color strip is used to represent all 256 colors in a palette.
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- Contour Level
- A range of data values that is to be distinguished from other
- ranges.
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- Contour Line
- The visual representation of the division between two contour
- levels.
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- Contour Plot
- A representation of a raster file that shows a series of contour lines
- separating different contour levels.
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- Control Button
- A visual button on the computer screen that performs some function
- when the left mouse button is clicked on it. Control buttons are
- usually rectangular with rounded edges and typically contain
- some descriptive text.
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- Current Directory
- The directory in the file system where ImageTool will look for
- files to be loaded.
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- Dimensions
- The number of rows and columns in the data matrix.
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- Frame
- A rectangle that encloses a group of windows and/or panels or a
- single window or panel.
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- HDF
- HDF (Hierarchical Data Format), created at NCSA, is a multi-
- object file structure designed to facilitate the sharing of data
- among people, projects, and machines on a network.
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- HSI
- The color model that represents color as a combination of hue,
- saturation, and intensity (brightness).
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- Image
- A pictorial representation of the raster file data that is displayed
- when you select the Load option. ImageTool uses a color
- representation.
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- Insertion point
- The point in a text field, indicated by a blinking triangular cursor,
- where text is displayed when you press on the keyboard.
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- Locator
- The dark gray area displayed in a scroll bar. It indicates the
- position within the text that is currently being viewed within the
- window.
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- Magnification
- The distance between adjacent data points. When the
- magnification is 1, each pixel or dot on the screen represents a data
- point.
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- Mouse
- Either of two related items: the hardware device that is used to
- move a pointer around on the computer screen or the pointer itself.
- The term refers collectively to both of these elements throughout
- this text. For example, the statement "move the mouse onto the
- canvas" means that you should move the hand-held hardware
- device on the grid until the mouse pointer has moved onto the
- canvas area. Movement of the hardware mouse will cause
- corresponding movement of the mouse pointer on the screen.
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- Mouse Button
- The three buttons on the mouse device. They are individually
- referred to as the left, middle, or right mouse button.
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- Origin Point
- The location on the canvas where the next drawing operation will
- begin.
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- Palette
- An array of 256 RGB colors. (The colors are not necessarily
- different.)
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- Palette File
- A file containing 256 RGB colors that can be used to initialize the
- color look-up table. When a raster file is first loaded, the palette
- used for the image is a duplicate of the color look-up table. You can
- then modify the palette or load a different palette from a palette file.
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- Paste Buffer
- The storage area where data that is cut or copied is stored so that it
- may be recalled.
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- Pitch
- Rotation around the horizontal axis (x axis), measured in degrees.
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- Plot, Line Plot
- Any visual representation of a set of data points. A line plot is any
- black-and-white representation of the data set.
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- Raster File
- A file containing a data matrix represented by a stream of bytes.
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- RGB
- The color model that represents all color as some combination of
- red, green, and blue.
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- Roll
- Rotation around the z axis, measured in degrees.
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- Scroll Arrows
- Small triangular figures in the extremities of a scroll bar that are
- used to interactively initiate scrolling.
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- Scroll Bar Content
- The light gray area of a scroll bar.
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- Selection
- An area of the canvas you designate interactively. Such an area
- can be used for a contour or 3D plot or an editing function.
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- Spectrum
- A diverse or varying range of colors. Unlike a palette, a spectrum
- consists of a range of differing colors and does not always consist
- of 256 colors. The fiddle operation alters the width and position of
- the spectrum, but cannot change the width of the palette.
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- Text Field
- An area in a window in which text may be entered and edited.
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- TTY Window
- A window that is used for three-way communication between you,
- the operating system, and ImageTool. ImageTool messages are
- displayed in this window. You may also use this window to enter
- system commands.
- Yaw
- Rotation about the vertical axis (y), measured in degrees.
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- 3D Plot
- A surface plot of the raster file representing the values in the 2D
- matrix as points in 3D space.
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