Image File Guidelines

Image files for figures, maths, etc. should be named according to the File Naming Convention, and referenced in the XML by a <graphic> or <inline-graphic> element as described in the sections on Figures and Maths. The format and resolution requirements for image files are described below.

Figures

All figures should have one or more version of the image file supplied. For figures which have multiple alternative versions (e.g. different resolutions or file formats for web and for print; e.g. colour for the Online version and Online PDF, and greyscale for the print PDF), each version of the figure file should be included. Figure files should be named per the file naming convention and use a format suffix as described in the section on Figures.

Image resolution and format should be set as per the guidelines below, unless otherwise advised by the PE.

Online Figures (specific-use="web-only" content-type="color" or "black-white")

Image files for all online figures for the web should be delivered in .jpg format. If a submitted author image is not in .jpg format, please convert to .jpg and ensure that:

  • If the width of a submitted image, a bitmap or a vector, is greater than 1500px, please reduce the width to 1500px. The aspect ratio of the image must be maintained when resizing.
  • If the width of a submitted vectorimage is less than 1500px, please increase the width to 1500px. The aspect ratio of the image must be maintained when resizing.
  • If the width of a submitted bitmap image is less than 1500px, please retain the image’s original pixel width (do NOT resize). Submitted raster images below 1500px should NOT be increased in size, as this will decrease the resolution and impact visual quality.
  • 300 dpi minimum for raster (bitmap) images
  • 1000 dpi minimum for line art (vector)
  • jpg quality maximum
  • color images should use RGB

Print Figures (specific-use="print-only" content-type="color" or "black-white")

Image files for all print figures can be delivered in either .tif, .eps, .png or .jpg format. Please retain the image in its original submitted format. For .eps files the minimum line weight should be 0.3pt. For .tif format, lossless compression (ZIP) should be enabled. If a submitted image is not in one of the formats listed above, please convert to the most appropriate format for the image in question, defaulting to .tif for raster graphics, and ensuring that:

  • 300 dpi minimum for raster (bitmap) images
  • 1000 dpi minimum for line art (vector)
  • jpg quality maximum (if using jpg format)
  • tif zip loseless compression enabled (if using tif format)
  • colour images should use CMYK

Alternative versions of images

When an image for a figure requires multiple alternative versions in order to meet the above requirements all versions of the image should be referenced in the XML using the <graphic> tag and the <alternatives> tag. Here are a few scenarios as examples:
  • If a figure should be in greyscale and the author supplied file meets both web and print requirements there would be need for only one graphic file, and the <alternatives> tag is not needed.
  • If a figure should be in greyscale and the author supplied file does not meet both sets of requirements there would be need for a graphic file formatted for the web and a graphic file formatted for creation of the print PDF, for example:
    <fig id="f0001">
<label>Figure 1</label>
<caption>
 <p>The location of the six neighbourhoods in the Lansing Capital Region.</p>
</caption>
<alternatives>
 <graphic xlink:href="CJUD_A_683403_F0001_OB.jpg" content-type="black-white" specific-use="web-only"/>
 <graphic xlink:href="CJUD_A_683403_F0001_PB.tif" content-type="black-white" specific-use="print-only"/>
</alternatives>
</fig>
  • If a figure should be in colour for online and in greyscale for print there would be a need for a graphic file in colour that is formatted for the web, and a graphic file in greyscale that is formatted for the print PDF, for example:
    <fig id="f0001">
<label>Figure 1</label>
<caption>
 <p>The location of the six neighbourhoods in the Lansing Capital Region.</p>
</caption>
<alternatives>
 <graphic xlink:href="CJUD_A_683403_F0001_OC.jpg" content-type="color" specific-use="web-only"/>
 <graphic xlink:href="CJUD_A_683403_F0001_PB.tif" content-type="black-white" specific-use="print-only"/>
 </alternatives>
</fig>

See the section on Figures and the Image Files section in the File Naming Convention for further instructions.

Display Math

Image files for display math should be in .gif format. The width of the image for display math should be no larger than 660 pixels. Images for display math should be cropped to exact size. The image should not include the label for numbered equations, schemes, etc.

Inline Images

Inline images should be saved in .gif format. The width of an inline image should be no more than 660 pixels. The height of an inline image should be sized for a line height of 13 pixels, though images may be taller than this for formulas that extend above or below the normal line height. Inline images should be cropped to exact size. Inline images should be created to appear correct with text that is sized at 10 points.

Graphical Abstracts

Online image files for graphical abstracts should be in .jpg format. The image width for graphical abstract images should be 525 pixels wide. If the submitted image is smaller than this white padding should be added to either side of the image. See the section on Article Abstract for more information.