The Save Image Panel

The Save Image panel (opened with File... Save Image) allows the contents of the graphics window to be saved as an image file. See the image tips below.

• The Image Size section includes
  • Units (centimeters/inches/millimeters/pixels/points) - the units used for describing the options below
  • Image width - width in units of image
  • Image height - height in units of image
  • Get Pixels, a button that sets units to pixels and shows the actual pixel dimensions of the display in the width and height fields
  • Image Setup, a button that opens the Image Setup preferences

  When Maintain current aspect ratio is on, the image width/height ratio is constrained to match the width/height ratio of the graphics window (not including borders). Entering the width automatically adjusts the height and vice versa.

  When Maintain current aspect ratio is off, width and height can both be set as desired. Grow to Fit resizes the graphics window to match the image aspect ratio by increasing one window dimension (i.e., width or height), while Shrink to Fit resizes the graphics window to match the image aspect ratio by decreasing one window dimension. If the window has not been resized to match the image aspect ratio (as specified by the values entered for width and height), a saved image will include more than what is visible in the display.

• The Image Information section includes
  • Description: further explanatory text (to be entered) which will be placed in a saved image file without affecting the image
  • An Image Credits button that opens the Image Credits preferences (text that will appear in a saved image file without affecting the image)
  • A Citing Chimera button that brings up information on citing Chimera in a browser window.

Clicking Save As dismisses the Save Image panel and causes the image to be redrawn in the appropriate size for saving. Because this is generally a different resolution than that shown on the screen, different portions of the image will "flash" within the graphics window. Other windows should not be placed over the graphics window while the image is being drawn. When the image computation is finished, a dialog for saving the image file will appear; a file name and file type (format) can be specified, or the save can be canceled. The possible formats are PNG, TIFF, JPEG, PS (PostScript), and EPS (encapsulated PostScript).

See also the command copy.

Background color can be changed using the menu (Actions... Color), the command set bg_color, or the Background preferences. If system hardware permits, starting Chimera with the --bgopacity option enables background transparency. Images saved with a transparent background are easier to composite with different backgrounds in image-editing applications.

Smoothness can be increased by increasing the resolution (number of pixels). Additionally, independent of resolution:

• the smoothness of curved surfaces in the stick, ball-and-stick, sphere, and ribbon molecular representations can be increased by raising subdivision quality in the Effects tool; this affects both the interactive display and saved images
• the smoothness of a molecular surface can be increased by increasing the density of vertices in the surface attributes panel; this affects both the interactive display and saved images
• the smoothness of straight edges in saved images can be increased by increasing the degree of supersampling in the Image Setup preferences; this does not affect the interactive display

Shininess of stick, ball-and-stick, sphere, and ribbon molecular representations, molecular surfaces, and surfaces generated by Volume Viewer and Multiscale Models can be adjusted with Shininess Control.

Lighting parameters can be adjusted in the Lighting tool. Apparent lighting can also be altered by moving clipping planes (see the Side View) or by changing depth cueing parameters in the Effects tool. Also in Effects, silhouette edges can clarify structures by emphasizing borders and discontinuities.

The command copy is another route to saving and printing images, but cannot yield resolutions higher than that of the screen.

See the Images for Publication tutorial for examples of image creation and a discussion of related issues (labeling, color space, and stereo).