Publication Quality Images

High Resolution (DPI) Images

Creating Resolution Specific Images

We often get the question:

Q.  How do I create a X DPI image using PyMol's 'ray' command?

The answer is deceivingly simple. There are two steps in the process. First, setup your scene and use ray like this

ray 2400, 2400

From this you will get a large square image. You can now resize it to X inches where X=A*B, A and B factors of 2400 (eg: 8 inch photo @ 300DPI, 4 inch photo at 600DPI, 2 inch photo @ 1200DPI). The formula for creating images is:

rayVal = inches * DPI

where rayVal is the value you pass to "ray". Thus, an 8 inch square photo at 72, 100, and 300 DPI would be created by the following commands:

ray 576,576   # 8inch * 72dpi
ray 800,800   # 8inch * 100dpi; or a 4inch * 200 DPI photo; or 1x800.
ray 2400,2400 # 8inch * 300dpi; 6"x400dpi, etc...

The new and better solution is to use the Png command with the dpi setting, such as

png fileName, dpi=300

If you don't have a new enough version of PyMOL that supports this, then the old solution is to use PhotoShop or GIMP to resize the photo to the appropriate height and width while making sure also to tell the PhotoShop or GIMP what resolution the image is.

GIMP 2.0

In Gimp, load your image (it'll most likely be very large) then

• Select:

Image ->
Scale Image ->
'Print Size & Scale Image Section' change 'New Width' to whatever width you decided on before.

• Save Image (File->Save)

You should be set.

Important Note

For those who are hung up on the idea that DPI is important please read this interesting explanation.

See Also

• Png
• Ray
• Draw
• CMYK
• the rest of the pages in this Category