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FAQ 

Why can't I submit a GIF image?

This image format is generated to display images on screen. Its compressed format is designed for easy transfer over the internet. It does not contain sufficient information for print publication.

Why can't I submit a JPEG image?

JPEG (Joint Photographic Experts Group) is an image compression format. This compression format is known as lossy compression, in that it deletes information that it considers unnecessary. This is a common standard on the WWW, but the data-loss generated by this compression makes it insufficient for print publication.

What if I am using a non-standard program to create my figures?

If you are not given the option to "save as" or "export as" a TIFF or EPS file, your best bet is to create a high-resolution PDF directly from the original application. This  requires the full version of Adobe Acrobat, if the application does not allow for saving in PDF format. (more info)

Can I use figures downloaded from the WWW?

Graphics found on the Web are low-resolution images that do not meet the standard for print publication.

If you are borrowing figures from another article or publication, you are required to supply APS with a publication-quality file. This is usually obtained by contacting the original author or publisher. This should be done when you are obtaining permission.  Previously Published Figures (more info)

How do I reduce the file size of  TIFF files?

- Be sure to save your image in the correct color space:

• color figures should be saved in RGB at 8 bits per channel

• if a figure is to be printed in grayscale, save it as grayscale - not RGB

- Crop out any extra white space around image

- Create figures at the size you would expect them to be printed in the journal

- Use LZW compression if given the option; it is a "lossless" compression

I can save my original figure in many formats, is TIFF the best?

Not always. Most application you may use to create/assemble your final figures will be doing so in a vector-based environment. Saving your figures as TIFF (raster-, pixel-based) will lock your image at that quality. If the TIFF is created at too low resolution it cannot be fixed. All of the flexibility of the original image (editable text and objects) will be lost.

Exporting as an EPS file or creating a PDF will retain all of the vector-quality of the original figure.

What is the difference between Raster and Vector images?

Vector graphics define each and every element in the image through mathematical code (postscript). Vector Graphics are resolution-independent (ADVANTAGE). This means that the image quality will remain consistent no matter how large or small the figure is sized.

Raster graphics are composed of pixels. This format is most commonly used for photographic images. Raster graphics are resolution-dependent (DISADVANTAGE), since resolution has an effect on the total number of pixels that are available within an image. The dimensions of these images cannot be increased without degrading the quality of the image.

Why can't I just change my 72 dpi TIFF figure to 600 dpi?

If the 72dpi image is already at full size, then increasing the resolution will actually lower the quality because this action will actually add more pixels to the existing image. The program will "guess" what to add and actually dilute the quality of the image. You are essentially adding "noise" to your image.

Are there any exceptions?

Digital cameras and other digital devices capture images at 72 dpi at a much larger physical size. These images can be re-sampled to achieve the appropriate resolution. (more info)

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05/02/2008