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IDL Reference Guide: Procedures and Functions |
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The IIMAGE procedure creates an iTool and associated user interface (UI) configured to display and manipulate image data.
| Note If no arguments are specified, the IIMAGE procedure creates an empty Image tool. |
This routine is written in the IDL language. Its source code can be found in the file iimage.pro in the lib/itools subdirectory of the IDL distribution.
For more information on using the iImage tool, see Working with Images.
IIMAGE[, Image[, X, Y]]
iTool Common Keywords: [, ANISOTROPIC_SCALE_2D=value] [, ANISOTROPIC_SCALE_3D=value] [, BACKGROUND_COLOR=value] [, DIMENSIONS=[x, y]] [, /DISABLE_SPLASH_SCREEN] [, /FIT_TO_VIEW] [, IDENTIFIER=variable] [, LOCATION=[x, y]] [, MACRO_NAMES=string or string array] [, NAME=string] [, /NO_SAVEPROMPT] [, OVERPLOT=iToolID] [, RENDERER={0 | 1}] [, SCALE_ISOTROPIC=value] [, STYLE_NAME=string] [, TITLE=string] [, VIEW_GRID=[columns, rows]] [, /VIEW_NEXT] [, VIEW_NUMBER=integer] [, VIEW_TITLE=string] [, VIEW_ZOOM=value]
Image Keywords: [, ALPHA_CHANNEL=array] [, BLUE_CHANNEL=array] [, CHANNEL=bitmask] [, CLIP_PLANES=array] [, GREEN_CHANNEL=array] [, GRID_UNITS=value] [, /HIDE] [, IMAGE_DIMENSIONS=[width, height]] [, IMAGE_LOCATION=[x, y]] [, INSERT_COLORBAR=value] [, /INTERPOLATE] [, /ORDER] [, RED_CHANNEL=array] [, RGB_TABLE=array] [, TRANSPARENCY=value] [, ZVALUE=value]
Axis Keywords: [, [XY]GRIDSTYLE={0 | 1 | 2 | 3 | 4 | 5 | 6}] [, [XY]MAJOR=integer] [, [XY]MINOR=integer] [, [XY]RANGE=[min, max]] [, [XY]SUBTICKLEN=ratio] [, [XY]TEXT_COLOR=RGB vector] [, [XY]TICKFONT_INDEX={0 | 1 | 2 | 3 | 4}] [, [XY]TICKFONT_SIZE=float] [, [XY]TICKFONT_STYLE={0 | 1 | 2 | 3}] [, [XY]TICKFORMAT=string or string array] [, [XY]TICKINTERVAL=value] [, [XY]TICKLAYOUT={0 | 1 | 2}] [, [XY]TICKLEN=value] [, [XY]TICKNAME=string array] [, [XY]TICKUNITS=string] [, [XY]TICKVALUES=vector] [, [XY]TITLE=string]
Either a vector, a two-dimensional, or a three-dimensional array representing the sample values to be displayed as an image.
If Image is a vector:
If Image is a two-dimensional array:
Image represents an array of x, y, and z values (either [[x0, y0, z0], [x1, y1, z1], ..., [xn, yn, zn]] or [[x0, x1, ..., xn], [y0, y1, ..., yn], [z0, z1, ..., zn]] where n is the length of the other dimension). In this case, the X and Y arguments, if present, will be ignored. A dialog will be presented that allows the option of gridding the data to a regular grid (the results of which will be displayed as an indexed-color image, using the z values as the image data values).
Image represents an array of sample values to be displayed as a color-indexed image. If X and Y are provided, the sample values are defined as a function of the corresponding (x, y) locations; otherwise, the sample values are implicitly treated as a function of the array indices of each element of Image.
If Image is a three-dimensional array:
Image is a 3 x n x m, n x 3 x m, or n x m x 3 array representing the red, green, and blue channels of the image to be displayed.
Image is a 4 x n x m, n x 4 x m, or n x m x 4 array representing the red, green, blue, and alpha channels of the image to be displayed.
Either a vector or a two-dimensional array representing the x-coordinates of the image grid.
If the Image argument is a vector:
If the Image argument is a two-dimensional array (for which neither dimension is 3):
Each element of X specifies the x-coordinates for a column of Image (e.g., X[0] specifies the x-coordinate for Image[0, *]).
Each element of X specifies the x-coordinate of the corresponding point in Image (Xij specifies the x-coordinate of Imageij).
X must be a vector, where each element of X specifies the x-coordinate for a column of Image ( X[0] specifies the x-coordinate for Image[*, 0, *]).
Either a vector or a two-dimensional array representing the y-coordinates of the image grid.
If the Image argument is a vector:
If the Image argument is a two-dimensional array:
Each element of Y specifies the y-coordinates for a row of Image (e.g., Y[0] specifies the y-coordinate for Image[*, 0]).
Each element of Y specifies the y-coordinate of the corresponding point in Image (Yij specifies the y-coordinate of Imageij).
Y must be a vector, where each element of Y specifies the y-coordinate for a row of Image (Y[0] specifies the y-coordinate for Image[*, *, 0]).
| Note Keywords to the IIMAGE routine that correspond to the names of registered properties of the iImage tool must be specified in full, without abbreviation. |
Set this keyword to a two-dimensional array representing the alpha channel pixel values for the image to be displayed. This keyword is ignored if the Image argument is present, and is intended to be used in conjunction with some combination of the RED_CHANNEL, GREEN_CHANNEL, and BLUE_CHANNEL keywords.
For two-dimensional anisotropic visualizations, set this keyword to a floating point value indicating the ratio of the Y dimension to the X dimension. The default is 0.7. If the dataspace and its contained visualizations are isotropic then this keyword is ignored.
For three-dimensional anisotropic visualizations, set this keyword to a floating point value indicating the ratio of the Z dimension to the X and Y dimensions. The default is 0.7. If the dataspace and its contained visualizations are isotropic then this keyword is ignored.
Set this keyword to an RGB value specifying the color to be used as the background color for the view. The default is [255, 255, 255] (white). The BACKGROUND_COLOR keyword can be used when a tool is being created or when a new visualization is being created in an existing tool with the use of the OVERPLOT, VIEW_NUMBER or VIEW_NEXT keywords. The background color is applied to the current view. For example, if multiple views have been created with the VIEW_GRID keyword, and the VIEW_NUMBER keyword is used to create a visualization in the second view, use of the BACKGROUND_COLOR keyword would set the background color in the second view only.
Set this keyword to a two-dimensional array representing the blue channel pixel values for the image to be displayed. This keyword is ignored if the Image argument is present, and is intended to be used in conjunction with some combination of the RED_CHANNEL, GREEN_CHANNEL, and ALPHA_CHANNEL keywords.
Set this keyword to a hexadecimal bitmask that defines which color channel(s) to draw. Each bit that is a 1 is drawn; each bit that is a 0 is not drawn. For example, 'ff0000'X represents a Blue channel write. The default is to draw all channels, and is represented by the hexadecimal value 'ffffff'X.
Set this keyword to an array of dimensions [4, N] specifying the coefficients of the clipping planes to be applied to this object. The four coefficients for each clipping plane are of the form [A, B, C, D], where Ax + By + Cz + D = 0. Portions of this object that fall in the half space Ax + By + Cz + D > 0 will be clipped. By default, the value of this keyword is a scalar (-1) indicating that no clipping planes are to be applied.
| Note A window is only able to support a limited number of clipping planes. Some of these clipping planes may already be in use by the tool to support specific data display features. If the total number of clipping planes exceeds the limit, an informational message is displayed. |
Set this keyword to a two-element vector of the form [width, height] to specify the dimensions of the drawing area of the specific tool in device units. The minimum width of the window correlates to the width of the menubar. The minimum window height is 100 pixels.
Set this keyword to disable the iTools splash screen. By default, the first time an iTool is run, the splash screen is displayed.
Set this keyword to automatically scale the newly-created visualization so that it fills the current view. This keyword is ignored if VIEW_ZOOM is present.
Set this keyword to a two-dimensional array representing the green channel pixel values for the image to be displayed. This keyword is ignored if the Image argument is present, and is intended to be used in conjunction with some combination of the RED_CHANNEL, BLUE_CHANNEL, and ALPHA_CHANNEL keywords.
Set this keyword to an integer specifying the units for the image grid. This keyword applies only when there is a map projection inserted. It has the following values:
Set this keyword to a boolean value indicating whether this object should be drawn:
Set this keyword to a named IDL variable that will contain the iToolID for the created tool. This value can then be used to reference this tool during overplotting operations or command-line-based tool management operations.
Set this keyword to a 2-element vector, [width, height], to specify the image dimensions (in data units). By default, the dimensions match the pixel width of the image.
Set this keyword to a 2-element vector, [x, y], to specify the image location (in data units). By default, the location is [0, 0].
If the newly-created visualization contains a color table (as specified by the RGB_TABLE keyword) set this keyword to automatically insert a colorbar. By default the colorbar will be positioned in the bottom center of the view. To manually position the colorbar, set this keyword equal to a two-element vector with values in the range (-1 to +1) specifying the location of the bottom left corner of the colorbar in normalized coordinates.
Set this keyword to one (1) to display the iImage tool using bilinear interpolation. The default is to use nearest neighbor interpolation.
Set this keyword to a two-element vector of the form [x, y] to specify the location of the upper left-hand corner of the tool relative to the display screen, in device units.
| Note Some X Window managers explicitly ignore any request from the client for window placement. See Positioning Top-Level Bases for additional information. |
Set this keyword to a scalar string or an array of strings that specifies the names of one or more macros to run. The macro names are retrieved and the macros are run sequentially after the iTool and (if applicable) any visualizations have been created. If a macro of the specified name does not exist, IDL generates an error and the routine exits.
Set this keyword to a string to specify the name for this visualization. The name is used for tool-related display purposes only.
Set this keyword to cause the iTool not to prompt the user to save changes when closing the tool. The default is to prompt the user to save changes.
Set this keyword to force the rows of the image data to be drawn from top to bottom. By default, image data is drawn from the bottom row up to the top row.
Set this keyword to an iToolID to direct the graphical output of the particular tool to the tool specified by the provided iToolID.
Set this keyword to 1 (one) to place the graphical output for the command in the current tool. If no current tool exists, a new tool is created.
Set this keyword to a two-dimensional array representing the red channel pixel values for the image to be displayed. This keyword is ignored if the Image argument is present, and is intended to be used in conjunction with some combination of the GREEN_CHANNEL, BLUE_CHANNEL, and ALPHA_CHANNEL keywords.
Set this keyword to override the value specified by the IDL_GR_WIN_RENDERER (Windows) or IDL_GR_X_RENDERER (UNIX) preference for the iTool. IDL will use the specified graphics renderer when drawing objects within the iTool window. Valid values are:
If your platform does not have a native OpenGL implementation, IDL uses its own software implementation regardless of the value of this property. See Hardware vs. Software Rendering for details.
Set this keyword to the number of the predefined IDL color table, or to either a 3 by 256 or 256 by 3 byte array of RGB color values. If no color tables are supplied, the tool will provide a default 256-entry linear grayscale ramp.
Set this keyword to indicate the scaling method to be used for the dataspace. Possible
values are:
| Note If the dataspace is anisotropic (either automatically or by setting SCALE_ISOTROPIC to 2), then the ANISOTROPIC_SCALE_2D or ANISOTROPIC_SCALE_3D keywords may be used to change the scaling. If the dataspace is isotropic then the ANISOTROPIC_SCALE_2D and ANISOTROPIC_SCALE_3D keywords are ignored. |
Set this keyword equal to a string that specifies the name of a user-defined or a system style. If a style of the specified name does not exist, IDL generates an error and the routine exits.
The style is applied using the following rules:
Set this keyword to a string to specify a title for the tool. The title is displayed in the title bar of the tool.
Set this keyword equal to an integer between 0 and 100 that specifies the percent transparency of the image visualization. The default is zero.
Set this keyword to a two-element vector of the form [columns, rows] to specify the view layout within the new tool. This keyword is only used if a new tool is being created (for example, if OVERPLOT, VIEW_NEXT, or VIEW_NUMBER are specified then VIEW_GRID is ignored).
Set this keyword to change the view selection to the next view following the currently-selected view before issuing any graphical commands. If the currently-selected view is the last one in the layout, then /VIEW_NEXT will cause the first view in the layout to become selected. This keyword is ignored if no current tool exists.
| Note The contents of the newly-selected view will be emptied unless /OVERPLOT is set. |
Set this keyword to change the currently-selected view to the view specified by the VIEW_NUMBER before issuing any graphical commands. The view number starts at 1, and corresponds to the position of the view within the graphics container (not necessarily the position on the screen). This keyword is ignored if no current tool exists.
| Note The contents of the newly-selected view will be emptied unless /OVERPLOT is set. |
Set this keyword equal to a scalar string that will be placed in a text annotation centered horizontally in the current view, near the top. The text will be created with the properties (size, style, color, etc.) defined for text annotations in the current tool style.
Set this keyword to a floating-point number giving the initial view zoom factor. For example, setting VIEW_ZOOM to 2.0 would give an initial zoom of 200%. The default is 1.0.
The index of the linestyle to be used for plot tickmarks and grids (i.e., when [XY]TICKLEN is set to 1.0). See LINESTYLE for a list of linestyles.
Set this keyword to an integer representing the number of major tick marks. The default is -1, specifying that IDL will compute the number of tickmarks. Setting MAJOR equal to zero suppresses major tickmarks entirely.
Set this keyword to an integer representing the number of minor tick marks. The default is -1, specifying that IDL will compute the number of tickmarks. Setting MINOR equal to zero suppresses minor tickmarks entirely.
Set this keyword to the desired data range of the axis, a 2-element vector. The first element is the axis minimum, and the second is the maximum.
Set this keyword to a floating-point scale ratio specifying the length of minor tick marks relative to the length of major tick marks. The default is 0.5, specifying that the minor tick mark is one-half the length of the major tick mark.
Set this keyword to an RGB value specifying the color for the axis text. The default value is [0, 0, 0] (black).
Set this keyword equal to one of the following integers, which represent the type of font to be used for the axis text:
| Tip Available fonts also include any additional TrueType fonts available to IDL. For a discussion of TrueType fonts, see About TrueType Fonts). Instead of using the [XYZ]TICKFONT_INDEX keyword, to access these additional fonts you may wish to create an iTools Style that sets the desired font for your axes. For more in iTools Styles, see What Are Styles?. |
Set this keyword to a floating-point integer representing the point size of the font used for the axis text. The default is 12.0 points.
Set this keyword equal to one of the following integers, which represent the style of font to be used for the axis text:
Set this keyword to a string, or an array of strings, in which each string represents a format string or the name of a function to be used to format the tick mark labels. If an array is provided, each string corresponds to a level of the axis. The TICKUNITS keyword determines the number of levels for an axis.
If the string begins with an open parenthesis, it is treated as a standard format string. See Format Codes.
If the string does not begin with an open parenthesis, it is interpreted as the name of a callback function to be used to generate tick mark labels. This function is defined with either three or four parameters, depending on whether TICKUNITS is specified.
The callback function is called with four parameters: Axis, Index, Value, and Level, where:
| Note For more information, see [XYZ]TICKFORMAT. |
Used with the LABEL_DATE function, this property can easily create axes with date/time labels.
Set this keyword to a floating-point scalar indicating the interval between major tick marks for the first axis level. The default value is computed according to the axis [XYZ]RANGE and the number of major tick marks ([XYZ]MAJOR). The value of this keyword takes precedence over the value set for the [XYZ]MAJOR keyword.
For example, if TICKUNITS = ['S', 'H', 'D'], and TICKINTERVAL = 30, then the interval between major ticks for the first axis level will be 30 seconds.
Set this keyword to integer scalar that indicates the tick layout style to be used to draw each level of the axis.
Valid values include:
| Note For all tick layout styles, at least one tick label will appear on each level of the axis (even if no major tick marks fall along the axis line). If there are no major tick marks, the single tick label will be centered along the axis. |
Set this keyword to a floating-point value that specifies the length of each major tick mark, measured in data units. The recommended, and default, tick mark length is 0.2. IDL converts, maintains, and returns this data as double-precision floating-point.
Set this keyword to a string array of up to 30 elements that controls the annotation of each tick mark.
Set this keyword to a string (or a vector of strings) indicating the units to be used for axis tick labeling. If more than one unit is provided, the axis will be drawn in multiple levels, one level per unit.
The order in which the strings appear in the vector determines the order in which the corresponding unit levels will be drawn. The first string corresponds to the first level (the level nearest to the primary axis line).
Valid unit strings include:
Numeric
Years
Months
Days
Hours
Minutes
Seconds
Time - Use this value to indicate that the tick values are time values; IDL will determine the appropriate time intervals and tick label formats based upon the range of values covered by the axis.
Numeric unit. This is the default setting.If any of the time units are utilized, then the tick values are interpreted as Julian date/time values. Note that the singular form of each of the time value strings is also acceptable (e.g, TICKUNITS = 'Day' is equivalent to TICKUNITS = 'Days').
| Note Julian values must be in the range -1095 to 1827933925, which corresponds to calendar dates 1 Jan 4716 B.C.E. and 31 Dec 5000000 C.E., respectively. |
Set this keyword to a floating-point vector of data values representing the values at each tick mark. If TICKVALUES is set to 0, the default, IDL computes the tick values based on the axis range and the number of major ticks. IDL converts, maintains, and returns this data as double-precision floating-point.
Set this keyword to a string representing the title of the specified axis.
Set this keyword to the height of the Z plane onto which the image will be projected. The default is zero. If the ZVALUE is zero then the image visualization is considered to be 2D. If the ZVALUE is nonzero, then the image visualization is considered to be 3D, and the dataspace associated with this image will be automatically switched to 3D.
In the IDL Intelligent Tools system, data can be imported from the IDL Command Line (as described in Example 1), or data can be imported via the File menu in the iTool window (as described in Examples 2 and 3). For detailed information on importing data via the iTool file menu, refer to Data Import Methods.
This example shows how use the IDL Command Line to load data into the iImage tool.
At the IDL Command Line, enter:
file = FILEPATH('mineral.png', $
SUBDIRECTORY = ['examples', 'data'])
data = READ_PNG(file)
IIMAGE, data, TITLE = 'Electron Image of Mineral Deposits'
Double-click the image to display image properties, and use the Image Palette setting to load the Stern Special predefined color table through the Load Predefined button in the Palette Editor.
Use the Text Annotation tool to insert a title at the top of the image. Select Insert 
Colorbars to insert a color bar at the bottom of the image. Double-click on the colorbar to display its properties, and change the Title setting to Stern Special.
The following figure displays the output of this example:
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This example shows how to use the iTool File Open command to load binary data into the iImage tool.
At the IDL Command Line, enter:
IIMAGE
Select File Open to display the Open dialog, then browse to find worldelv.dat in the examples/data directory in the IDL distribution, and click Open.
In the Binary Template dialog, click New Field, and enter the following information in the New Field dialog:
Click OK to close the New Field dialog and the Binary Template dialog, and the image is displayed.
| Note For more information on using the Binary Template to import data, see Using the BINARY_TEMPLATE Interface. |
Double-click the image to display image properties, and use the Image Palette setting to load the STD GAMMA-II predefined color table through the Load Predefined button in the Palette Editor.
The following figure displays the output of this example:
This example shows how to use the IDL Import Data Wizard to load image data into the iImage tool.
At the IDL Command Line, enter:
IIMAGE
Select File Import to display the IDL Import Data wizard.
Define the edges within the image by selecting Operations Filter Sobel Filter.
The following figure displays the output of this example:
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IDL Online Help (March 06, 2007)
