beta: in, optional, type=float, default=3.0
The beta factor in a Hyperpolic Sine stretch. Available only with 2D images.
bottom: in, optional, type=integer, default=0
If the SCALE keyword is set, the image is scaled before display so that all
displayed pixels have values greater than or equal to BOTTOM and less than
or equal to TOP. Available only with 2D images.
boxcolor: in, optional, type=string, default='gold'
The name of the color of the rubber-band selection box.
clip: in, optional, type=float, default=2
A number between 0 and 50 that indicates the percentage of pixels to clip
off either end of the image histogram before performing a linear stretch.
Available only with 2D images.
exclude: in, optional, type=numeric
The value to exclude in a standard deviation stretch.
exponent: in, optional, type=float, default=4.0
The logarithm exponent in a logarithmic stretch. Available only with 2D images.
filename: in, optional, type=string
The name of a file that IDL can read with READ_IMAGE (e.g, GEOTIFF, TIF, JPEG, PNG, etc.).
gamma: in, optional, type=float, default=1.5
The gamma factor in a gamma stretch. Available only with 2D images.
group_leader: in, optional, type=long
The widget identifier of the group leader for this program. When the group leader
dies, this program will be destroyed, too.
interpolate: in, optional, type=boolean, default=0
Set this keyword to interpolate with bilinear interpolation the display image as it
is sized to its final position in the display window. Interpolation will potentially
create image values that do not exist in the original image. The default is to do no
interpolation, so that image values to not change upon resizing. Interpolation can
result in smoother looking final images.
map: in, optional, type=structure
A cgMap object for navigating the input image.
maxvalue: in, optional, type=varies
If this value is defined, the data is linearly scaled between MINVALUE
and MAXVALUE. MAXVALUE is set to MAX(image) by default. Setting this
keyword to a value automatically sets `SCALE` to 1. If the maximum value of the
image is greater than 255, this keyword is defined and SCALE=1.
mean: in, optional, type=float, default=0.5
The mean factor in a logarithmic stretch. Available only with 2D images.
minvalue: in, optional, type=varies
If this value is defined, the data is linearly scaled between MINVALUE
and `MAXVALUE`. MINVALUE is set to MIN(image) by default. Setting this
keyword to a value automatically sets SCALE=1. If the minimum value of the
image is less than 0, this keyword is defined and SCALE=1.
missing_color: in, optional, type=string, default='white'
The color name of the missing value. Available only with 2D images.
missing_index: in, optional, type=integer, default=255
The index of the missing color in the final byte scaled image. Available only with 2D images.
missing_value: in, optional, type=integer
The number that represents the missing value in the image. Available only with 2D images.
multiplier: in, optional, type=float
The multiplication factor in a standard deviation stretch. The standard deviation
is multiplied by this factor to produce the thresholds for a linear stretch.
ncolors: in, optional, type=integer, default=256
If this keyword is supplied, the `TOP` keyword is ignored and the TOP keyword
is set equal to NCOLORS-1. This keyword is provided to make cgImage easier
to use with the color-loading programs such as cgLOADCT::
cgLoadCT, 5, NColors=100, Bottom=100
cgImage, image, NColors=100, Bottom=100
Setting this keyword to a value automatically sets SCALE=1. Available only with 2D images.
negative: in, optional, type=boolean, default=0
Set this keyword if you want to display the image with a negative or reverse stretch.
Available only with 2D images.
palette: in, optional, type=byte
Set this keyword to a 3x256 or 256x3 byte array containing the RGB color
vectors to be loaded before the image is displayed. Such vectors can be
obtained, for example, from cgLoadCT with the RGB_TABLE keyword::
cgLoadCT, 4, /BREWER, /REVERSE, RGB_TABLE=palette
cgImage, cgDemoData(7), PALETTE=palette
scale: in, optional, type=boolean, default=0
Set this keyword to byte scale the image before display. If this keyword is not set,
the image is not scaled before display. This keyword will be set automatically by using
any of the keywords normally associated with byte scaling an image. Available only with
2D images. If set, STRETCH is set to 1, unless it is set to another value.
stretch: in, optional, type=integer/string, default=1
The type of scaling performed prior to display. May be specified as a number
or as a string (e.g, 3 or "Log"). Available only with 2D images.
Number Type of Stretch
0 None No scaling whatsoever is done.
1 Linear scaled = BytScl(image, MIN=minValue, MAX=maxValue)
2 Clip A histogram stretch, with a percentage of pixels clipped at both the top and bottom
3 Gamma scaled = GmaScl(image, MIN=minValue, MAX=maxValue, Gamma=gamma)
4 Log scaled = LogScl(image, MIN=minValue, MAX=maxValue, Mean=mean, Exponent=exponent)
5 Asinh scaled = AsinhScl(image, MIN=minValue, MAX=maxValue, Beta=beta)
6 SquareRoot A linear stretch of the square root histogram of the image values.
7 Equalization A linear stretch of the histogram equalized image histogram.
8 Gaussian A Gaussian normal function is applied to the image histogram.
9 MODIS Scaling done in the differential manner of the MODIS Rapid Response Team
and implemented in the Coyote Library routine ScaleModis.
sigma: in, optional, type=float, default=1.0
The sigma scale factor in a Gaussian stretch. Available only with 2D images.
title: in, optional, type=string, default=""
Set this keyword to the title of the plot window.
top: in, optional, type=integer, default=255
If the SCALE keyword is set, the image is scaled before display so that all
displayed pixels have values greater than or equal to BOTTOM and less than
or equal to TOP. Available only with 2D images.
zoomfactor: in, optional, type=string, default=3
Use this keyword to set the starting zoom factor. The values you can use are as follows::
0: 'Actual'
1: '2x'
2: '3x'
3: '4x'
4: '5x'
5: '6x'
6: '7x'
7: '8x'
8: '12x'
9: '16x'