Difference between revisions of "Png"

Latest revision as of 13:31, 9 February 2015

png writes a png format image file of the current image to disk.

Usage

png filename[, width[, height[, dpi[, ray[, quiet]]]]]

filename = string: file path to be written
width = integer or string: width in pixels (integer or string without units), inches (in), or centimeters (cm). If unit suffix is given, `dpi` argument is required as well. If only one of `width` or `height` is given, the aspect ratio of the viewport is preserved. {default: 0 (current)}
height = integer or string: height (see width) {default: 0 (current)}
dpi = float: dots-per-inch {default -1.0 (unspecified)}
ray = 0 or 1: should ray be run first {default: 0 (no)}
quiet = 0 or 1: if 1, logged output is suppressed. {default: 0}

Example

png ~/Desktop/test.png, width=10cm, dpi=300, ray=1

PyMOL API

cmd.png(string filename, int width=0, int height=0, float dpi=-1, int ray=0, int quiet=0)

Comments

Transparent Backgrounds

Use the `ray_opaque_background` setting to output images with transparent backgrounds.

set ray_opaque_background, 0

This can be useful for presentations, images that are placed on top of a background of nonuniform color (e.g. gradients), and images that overlap text or other images.

DPI Setting

Use the DPI option to have PyMol set the DPI of your image. Executing the command

png /tmp/ex.png, width=1200, height=1200, dpi=300, ray=1

will ouput a four-inch square image at 300dpi. Leaving off the dpi parameter would yield a 1200x1200 image at your system's default pixel density (e.g. 72 or 96 dpi). This saves the intermediate step of having to use GIMP/PhotoShop/etc to rescale your photos for publication.

@@ Line 1: / Line 1: @@
 '''png''' writes a png format image file of the current image to disk.
-===USAGE===
+== Usage ==
-  png filename, dpi, ray
+  png filename[, width[, height[, dpi[, ray[, quiet]]]]]
-* '''dpi''', sets the dots per inch (dpi) of the final image
+* '''filename''' = string: file path to be written
-* '''ray''', whether or not PyMOL ray traces the image before saving
+* '''width''' = integer or string: width in pixels (integer or string without units), inches (in), or centimeters (cm). If unit suffix is given, `dpi` argument is required as well. If only one of `width` or `height` is given, the aspect ratio of the viewport is preserved. {default: 0 (current)}
+* '''height''' = integer or string: height (see width) {default: 0 (current)}
+* '''dpi''' = float: dots-per-inch {default -1.0 (unspecified)}
+* '''ray''' = 0 or 1: should ray be run first {default: 0 (no)}
+* '''quiet''' = 0 or 1: if 1, logged output is suppressed.  {default: 0}
-===PYMOL API===
+== Example ==
+ png ~/Desktop/test.png, width=10cm, dpi=300, ray=1
+== PyMOL API ==
 <source lang="python">
-cmd.png( string file, dpi, ray )
+cmd.png(string filename, int width=0, int height=0, float dpi=-1, int ray=0, int quiet=0)
 </source>
-===COMMENTS===
+== Comments ==
-====Blank Screen Shots====
-If, when you execute the [[Png]] command, you get blank images, you may have to [[Ray]] trace your image first, before running the [[Png]] command.  This occurs when there is no device context for the image, such as when running PyMOL in quiet gui-less mode.  If the ray tracing is taking too long due to scene complexity or size, then please see the [[Ray]] page or search the wiki for information about making movies with PyMOL (there are many ways to [[:Category:Performance|speed]] up rendering).
 ====Transparent Backgrounds====
-See [[Ray_opaque_background]].  This is very useful for presentations, or images that are placed on top of a background of nonuniform color, or if you simply want a transparent background for your images.
+Use the `[[ray_opaque_background]]` setting to output images with transparent backgrounds.
+  set ray_opaque_background, 0
+This can be useful for presentations, images that are placed on top of a background of nonuniform color (e.g. gradients), and images that overlap text or other images.
 ====DPI Setting====
-Use the DPI option to have PyMol set the DPI of your image.  If I execute
+Use the DPI option to have PyMol set the DPI of your image.  Executing the command
-<source lang="python">ray 1200,1200</source>
+<source lang="python">png /tmp/ex.png, width=1200, height=1200, dpi=300, ray=1</source>
-then execute
+will ouput a four-inch square image at 300dpi.  Leaving off the '''dpi''' parameter would yield a 1200x1200 image at your system's default pixel density (e.g. 72 or 96 dpi).  This saves the intermediate step of having to use GIMP/PhotoShop/etc to rescale your photos for publication.
-<source lang="python">png /tmp/ex.png, dpi=300</source>
-I will get a four-inch square image at 300dpi.  Leaving off the '''dpi''' flag would net me a 1200x1200 image at 72dpi.  This saves the intermediate step of having to use GIMP/PhotoShop/etc to rescale your photos for publication.
 [[Category:Commands|Png]]
 [[Category:Publication_Quality|Png]]
 [[Category:Performance|Png]]