The WRITE_TIFF procedure can write TIFF files with one or more channels, where each channel can contain 1, 4, 8, 16, or 32-bit integer pixels, or floating-point values.
WRITE_TIFF, Filename [, Image] [, /APPEND] [, BITS_PER_SAMPLE={1 | 4 | 8}] [, RED=value] [, GREEN=value] [, BLUE=value] [, COMPRESSION={0 | 2 | 3}] [, GEOTIFF=structure] [, /LONG | , /SHORT | , /FLOAT] [, ORIENTATION=value] [, PLANARCONFIG={1 | 2}] [, UNITS={1 | 2 | 3}] [, /VERBOSE] [, XRESOL=pixels/inch] [, YRESOL=pixels/inch]
A scalar string containing the full pathname of the TIFF to write.
The array to be written to the TIFF. If Image has dimensions (k,n,m), a k-channel TIFF is written. Image should be in top to bottom scan line order. By default, this array is converted to byte format before being written (see the LONG, SHORT and FLOAT keywords below). Note that many TIFF readers can read only one- or three-channel images.
| Note |
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This argument is obsolete. The Order argument has been replaced by the ORIENTATION keyword. Code that uses the Order argument will continue to work as before, but new code should use the ORIENTATION keyword instead.
Set this keyword to specify that the image should be added to the existing file, creating a multi-image TIFF file.
Set this keyword to either 1, 4, or 8 to create a grayscale image file with the specified number of bits per pixel. For 1-bit (bi-level) images, an output pixel is assigned the value 1 (one) if the corresponding input pixel is nonzero. For 4-bit grayscale images, the input pixel values must be in the range 0 through 15, or the image will be garbled. The default is BITS_PER_SAMPLE=8. This keyword is ignored if an RGB image or color palette is present, or if one of the FLOAT, LONG, or SHORT keywords is set.
Set this keyword to select the type of compression to be used:
| Note |
Set this keyword to write the pixel components as floating-point entities (the default is 8-bit).
Set this keyword to an anonymous structure containing one field for each of the GeoTIFF tags and keys to be written into the file. The GeoTIFF structure is formed using fields named from the following table.
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Set this keyword to write the pixel components as unsigned 32-bit entities (the default is 8-bit).
Set this keyword to an integer value to specify the orientation of the TIFF image. The default is ORIENTATION=1.
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Possible values are:
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This keyword determines the order in which a multi-channel image is stored and written. It has no effect with a single-channel image. Set this keyword to 2 to if the Image parameter is interleaved by "plane", or band, and its dimensions are (Columns, Rows, Channels). The default value is 1, indicating that multi-channel images are interleaved by color, also called channel, and its dimensions are (Channels, Columns, Rows).
As a special case, this keyword may be set to 2 to write an RGB image that is contained in three separate arrays (color planes), stored in the variables specified by the RED, GREEN, and BLUE keywords. Otherwise, omit this parameter (or set it to 1).
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If you are writing a Palette color image, set these keywords equal to the color table vectors, scaled from 0 to 255.
If you are writing an RGB interleaved image (i.e., if the PLANARCONFIG keyword is set to 2), set these keywords to the names of the variables containing the three image components.
Set this keyword to write the pixel components as unsigned 16-bit entities (the default is 8-bit).
Set this keyword to one of the following values to specify the units used for the values specified by the XRESOL and YRESOL keywords:
Set this keyword to produce additional diagnostic output during the write.
Set this keyword to the horizontal resolution, in pixels per unit, where the unit is specified by the value of the UNITS keyword (inches, by default). The default value of XRESOL is 100. Note that while this value is stored in the TIFF file, it may be interpreted by the TIFF reader in a variety of ways, or ignored.
Set this keyword to the vertical resolution, in pixels per unit, where the unit is specified by the value of the UNITS keyword (inches, by default). The default value of YRESOL is 100. Note that while this value is stored in the TIFF file, it may be interpreted by the TIFF reader in a variety of ways, or ignored.
Create a pseudo screen dump from the current window. Note that this works only on a PseudoColor (8-bit) display:
WRITE_TIFF, 'test.tiff', TVRD()
Write a three-channel image from three one-channel (two-dimensional) arrays, contained in the variables Red, Green, and Blue:
WRITE_TIFF, 'test.tif', Red, Green, Blue, PLANARCONFIG=2
Write and read a multi-image TIFF file. The first image is a 16-bit single channel image stored using compression. The second image is an RGB image stored using 32-bits/channel uncompressed.
; Write the image data:
data = FIX(DIST(256))
rgbdata = LONARR(3,320,240)
WRITE_TIFF,'multi.tif',data,COMPRESSION=1,/SHORT
WRITE_TIFF,'multi.tif',rgbdata,/LONG,/APPEND
; Read the image data back
ok = QUERY_TIFF('multi.tif',s)
IF (ok) THEN BEGIN
FOR i=0,s.NUM_IMAGES-1 DO BEGIN
imp = QUERY_TIFF('multi.tif',t,IMAGE_INDEX=i)
img = READ_TIFF('multi.tif',IMAGE_INDEX=i)
HELP,t,/STRUCTURE
HELP,img
ENDFOR
ENDIF
Introduced: 5.0
ITIFF support added: 5.6