psimage

psimage - Place images or EPS files on maps

Synopsis

psimage imagefile [ -W[-]width[/height] | -Edpi ] [ -Cxpos/ypos[/justify] ] [ -Fpen ] [ -G[b|f|t]color ] [ -I ] [ -Jparameters ] [ -Jz|Zparameters ] [ -K ] [ -M ] [ -Nnx[/ny] ] [ -O ] [ -P ] [ -Rwest/east/south/north[/zmin/zmax][r] ] [ -U[just/dx/dy/][c|label] ] [ -V[level] ] [ -X[a|c|f|r][x-shift[u]] ] [ -Y[a|c|f|r][y-shift[u]] ] [ -ccopies ] [ -p[x|y|z]azim/elev[/zlevel][+wlon0/lat0[/z0]][+vx0/y0] ] [ -t[transp] ]

Note: No space is allowed between the option flag and the associated arguments.

Description

psimage reads an Encapsulated PostScript file or a raster image file and plots it on a map. The image can be scaled arbitrarily, and 1-bit raster images can be (1) inverted, i.e., black pixels (on) becomes white (off) and vice versa, or (2) colorized, by assigning different foreground and background colors, and (3) made transparent where one of back- or foreground is painted only. As an option, the user may choose to convert colored raster images to grayscale using TV’s YIQ-transformation. For raster files, the user can select which color to be made transparent. The user may also choose to replicate the image which, when preceded by appropriate clip paths, may allow larger custom-designed fill patterns to be implemented (the -Gp mechanism offered in most GMT programs is limited to rasters smaller than 146 by 146).

Required Arguments

imagefile
This must be an Encapsulated PostScript (EPS) file or a raster image. An EPS file must contain an appropriate BoundingBox. A raster file can have a depth of 1, 8, 24, or 32 bits and is read via GDAL. If GDAL was not configured during GMT installation then only Sun raster files are supported natively.
-Edpi
Sets the dpi of the image in dots per inch, or use -W.
-W[-]width[/height]
Sets the width (and height) of the image in plot coordinates (inches, cm, etc.). If height is not given, the original aspect ratio of the image is maintained. If width is negative we use the absolute value and interpolate image to the device resolution using the PostScript image operator. Alternatively, use -E.

Optional Arguments

-Cxpos/ypos[/justify]
Sets position of the image in plot coordinates (inches, cm, etc.) from the current origin of the plot. By default, this defines the position of the lower left corner of the image, but this can be changed by specifying justification [0/0/BL].
-Fpen
Draws a rectangular frame around the image with the given pen [no frame].
-Jparameters (more ...)
Select map projection.
-Jz|Zparameters (more ...)
Set z-axis scaling; same syntax as -Jx.
-K (more ...)
Do not finalize the PostScript plot.
-M
Convert color image to monochrome grayshades using the (television) YIQ-transformation.
-Nnx[/ny]
Replicate the image nx times horizontally and ny times vertically. If ny is omitted, it will be identical to nx [Default is 1/1].
-O (more ...)
Append to existing PostScript plot.
-P (more ...)
Select “Portrait” plot orientation.
-Rwest/east/south/north[/zmin/zmax][r]
west, east, south, and north specify the region of interest, and you may specify them in decimal degrees or in [+-]dd:mm[:ss.xxx][W|E|S|N] format. Append r if lower left and upper right map coordinates are given instead of w/e/s/n. The two shorthands -Rg and -Rd stand for global domain (0/360 and -180/+180 in longitude respectively, with -90/+90 in latitude). Alternatively, specify the name of an existing grid file and the -R settings (and grid spacing, if applicable) are copied from the grid. Using -Runit expects projected (Cartesian) coordinates compatible with chosen -J and we inversely project to determine actual rectangular geographic region. For perspective view (-p), optionally append /zmin/zmax. In case of perspective view (-p), a z-range (zmin, zmax) can be appended to indicate the third dimension. This needs to be done only when using the -Jz option, not when using only the -p option. In the latter case a perspective view of the plane is plotted, with no third dimension.

For perspective view p, optionally append /zmin/zmax. (more ...)

-U[just/dx/dy/][c|label] (more ...)
Draw GMT time stamp logo on plot.
-V[level] (more ...)
Select verbosity level [c].

-X[a|c|f|r][x-shift[u]]

-Y[a|c|f|r][y-shift[u]] (more ...)
Shift plot origin.
-ccopies (more ...)
Specify number of plot copies [Default is 1].

These options are for 1-bit images only. They have no effect when plotting other images or PostScript files.

-G[b|f|t]color
-Gb
Sets background color (replace white pixel) of 1-bit images. Use - for transparency (and set -Gf to the desired color).
-Gf
Sets foreground color (replace black pixel) of 1-bit images. Use - for transparency (and set -Gb to the desired color).
-I
Invert 1-bit image before plotting. This is what is done when you use -GP in other GMT programs.

These options are for 8-, 24-, and 32-bit raster images only. They have no effect when plotting 1-bit images or PostScript files.

-Gt
Assigns the color that is to be made transparent. Sun Raster files do not support transparency, so indicate here which color to be made transparent.
-p[x|y|z]azim/elev[/zlevel][+wlon0/lat0[/z0]][+vx0/y0] (more ...)
Select perspective view. (Requires -R and -J for proper functioning).
-t[transp] (more ...)
Set PDF transparency level in percent.
-^
Print a short message about the syntax of the command, then exits (NOTE: on Windows use just -).
+
Print an extensive usage (help) message, including the explanation of any module-specific option (but not the GMT common options), then exits.
-?
Print a complete usage (help) message, including the explanation of options, then exits.
--version
Print GMT version and exit.
--show-datadir
Print full path to GMT share directory and exit.

Examples

To plot the image contained in the 8-bit raster file scanned_face.ras, scaling it to 8 by 10 cm (thereby possibly changing the aspect ratio), and making the white color transparent, use

gmt psimage scanned_face.ras -W8c/10c -Gtwhite > image.ps

To plot the image logo.jpg, scaling it be 1 inch wide (height is scaled accordingly), and outline with a thin, blue pen, use

gmt psimage logo.jpg -W1i -Fthin,blue > image.ps

To include an Encapsulated PostScript file tiger.eps with its upper right corner 2 inch to the right and 1 inch up from the current location, and have its width scaled to 3 inches, while keeping the aspect ratio, use

gmt psimage tiger.eps -C2i/1i/TR -W3i > image.ps

To replicate the 1-bit raster image template 1_bit.ras, colorize it (brown background and red foreground), and setting each of 5 by 5 tiles to be 1 cm wide, use

gmt psimage 1_bit.ras -Gbbrown -Gfred -N5 -W1c > image.ps

See Also

gmt, gmtcolors, psxy, convert(1)