magcube Documentation

magcube - Scale cube up or down using bilinear interpolator
This program magnifies or demagnifies the core of a cube file.
That is, it will scale a cube up or down in the sample and line
dimensions. When scaling up, the program uses a bilinear
interpolator as opposed to a nearest neighbor interpolator.
The bilinear interpolator gives a smooth appearance to
interpolated pixels, whereas the nearest neighbor interpolator
gives a blocky appearance. When scaling down, the program
averages. For example, when scaling the image down by a factor
of 3, the program will average 9 pixels (a 3x3 window) to
generate each output pixel. Backplanes, sideplanes and bottom-
planes are not transfered from the input to the output cube.

Note, this program will only scale the cube in the line and
sample directions. Thus, it cannot do band interpolation or
compression; however, sample and line scales are independent
so that pixel aspect distortions can be corrected. Also, map
projection parameters from the input cube will be preserved
if the sample and line scales remain the same; otherwise the
map projection parameters will not be propagated to the
output cube. If a nearest neighbor interpolator is desired
for scaling use the "dsk2dsk" program and specify increment
values in SFROM.

Programmer: Jeff Anderson, U.S.G.S., Flagstaff, AZ

Input cube file name
  (default extension is .cub)

NONE

Output cube file name
  (default extension is .cub)

NONE

Sample scaling factor

--

Line scaling factor

--

Number of samples in output cube

--

Number of lines in output cube

--

Output pixel type
 NULL = input type
    1 = 8 bit
    2 = 16 bit
    3 = 32 bit

--

Output min/max data range

--

Valid percentage for scaling
  down

0.5

ADDITIONAL NOTES:

Parm	Description
FROM	Input cube file name. If the file extension is omitted, then ".cub" will be assumed.
TO	Output cube file name. If the file extension is omitted, then ".cub" will be assumed.
SSCALE	The scaling factor for the sample direction. A value greater than 1 enlarges the cube in the sample direction. Thus, 2.5 would increase the number of samples in the cube by 2.5 times. Similarly, a value less than 1 shrinks the cube in the sample direction. NOTE: This parameter CANNOT be used in conjuction with the ONS parameter.
LSCALE	The scaling factor for the line direction. A value greater than 1 enlarges the cube in the line direction. Thus, 2.5 would increase the number of lines in the cube by 2.5 times. Similarly, a value less than 1 shrinks the cube in the line direction. NOTE: This parameter CANNOT be used in conjuction with the ONL parameter.
ONS	The number of samples desired in the output cube. NOTE: This parameter CANNOT be used in conjunction with the SSCALE parameter.
ONL	The number of lines desired in the output cube. NOTE: This parameter CANNOT be used in conjunction with the LSCALE parameter.
OTYPE	Output pixel data type. Permitted values are: NULL = output type is same as input file pixel type 1 = 8-bit (integer with type conversion parameters) 2 = 16-bit (integer with type conversion parameters) 3 = 32-bit (floating point) When processed data are being written back into the input file, the output pixel type must be the same as the existing pixel type in the input file.
ORANGE	Output pixel data range. If ORANGE is NULL, then the CORE_BASE and CORE_MULTIPLIER in the output file will be set to represent the same range of data as the input file. If OTYPE=1 (8-bit) or OTYPE=2 (16-bit), then the CORE_BASE and CORE_MULTIPLIER in the output file will be set to values that allow representing the specified range of output values. Output values outside this range will be stored as a special "representation saturation" value. The ORANGE parameter is ignored if OTYPE=3 (32-bit) since the CORE_BASE and CORE_MULTIPLIER are not applicable to floating point pixel values. **NOTE** For a more detailed explanation of ORANGE, tutor the orange.pdf.
VPER	This parameter is only used when scaling an image down. It is used to specify what percentage of the pixels need to be valid (non-special pixels). For example, scaling down by a factor of two results in a 3x3 window (nine pixels) being reduced to one pixel. If VPER is set a 0.75 then at least seven of the nine pixels must be valid. If the critera is met then the resulting value of the output pixel will be the average of the valid input pixels. Otherwise the output pixel will be set to the input pixel which is closest to the center of the window.