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SERNEC Live Plant Image Collection Guidelines

From 2008 through April 2009, a group of individuals with experience taking a significant number of live plant images, with an interest in or responsibility for maintaining a collection of live plant images, or with an interest in using live plant images to create educational products conducted an electronic discussion focused on the steps necessary to create a community collection of live plant images.  The discussion was conducted under the auspices of the Imaging Standards working group of SERNEC (the Southeast Regional Network of Expertise and Collections) and the group was known informally as the "SERNEC Live Plant Imaging Subgroup".  

The goal of this discussion was to arrive at a consensus about a number of issues that needed to be resolved as a prerequisite to the creation of the community collection, dubbed the SERNEC Live Plant Image Collection (SLPIC).  This webpage summarizes the major recommendations of the group and provides examples of how Bioimages has implemented these recommendations.

I. Intellectual property issues

A. Copyright

1. Photographers retain copyright to their images unless they decide to release them into the public domain. 

2. In the image metadata, a copyright statement, e.g. "(c) 2010 Steven J. Baskauf", should be associated with the term dcterms:rights.  The copyright owner should be listed under the term xmpRights:Owner.  (These are required terms under the MTRG draft standards.)  See for an RDF example and namespace declarations and for an example of web presentation for the same image.

B. Licensing

1. Photographers participating in the SLPIC agree to license their contributed images under a Creative Commons ("CC"; ) license no more restrictive than Attribution-Noncommercial-Share Alike 3.0 (BY-NC-SA) or to release them to the Public Domain.  Less restrictive (allowed) licenses would include: BY, BY-NC, and BY-SA.  "No derivative works" (ND) licenses are not appropriate in the SLPIC.

In the context of the SERNEC live plant image collection, the Share Alike element is understood to mean that derivative works of the image itself (e.g. images that are cropped, annotated, enhanced, or otherwise modified) created by the user must be licensed under the same license as the original image.  The Share Alike element is understood to not apply to other content that may appear with the unmodified image (i.e. on the same web or print page).  That other content may be licensed according to the wishes of its creator. 

2. By standardizing the most restrictive allowable license, users of the collection will be assured that any images they find will be available for non-commercial personal or educational use without the need to scrutinize the licensing terms of each image. 

3. Photographers may continue to use their images as they wish, including publishing them on their own or other websites and making individual arrangements to license them to commercial users. 

4. In the image metadata, the licensing statement should be associated with the term xmpRights:UsageTerms.  See the RDF and HTML files listed above for examples.

II. Quality control

A. Accuracy of identification

1. Accuracy in identification will be achieved primarily through the care taken by the photographers.   It is assumed that the photographers will have some skill in plant identification or are working with someone with such skills

2. It is understood and expected that images included in the collection will be subject to annotation by SERNEC taxonomists.  The types of images, way that they are photographed, and metadata associated with the images will facilitate verification of the identity of the subject of the images.  In particular:

a.  the inclusion of multiple standardized images for each individual will make it possible to know that image of less informative features are associated with other images that are more diagnostic.

b. robust metadata should be linked to the image to ensure that the date and location of the image is consistent with the known phenology and distribution of the species to which the individual featured in the image has been assigned.  (more on this later...).  The metadata elements should be organized according to the Darwin Core standard for biodiversity resources and the GBIF/TDWG Media Resources Task Group (MRTG) proposed standards

c. the resolution and quality of the image should be sufficient to allow the details shown in the image to be enlarged and observed.  In particular, a minimum resolution of 3 megapixels is required, with at least 6 megapixels preferred. 

B. Standardization of images

1. The SERNEC Live Plant Imaging Subgroup has no official authority and can't "make" anybody follow any particular standards or procedures.  However, it is assumed that those who voluntarily participate in the group share its goals, which are to aggregate images that will be used to facilitate species identification and recognition, and to be used as an educational resource.  If there are competing considerations between these uses and others such as artistic or commercial uses, the educational considerations trump the others. With those goals in mind, the group has set some minimal standards for an image to qualify as a part of the SLPIC.

2. The full recommendations of SLPIC are rather demanding and not all photographers are able or willing to put in the time and effort required to fully meet those recommendations.  To balance the constraints of the photographers (limited time to take many photographs, limited time to go through old images and reconstruct the missing metadata, images already modified in ways that don't meet the standards, preference to take images in ways not specified in the standards) with the demands of users (higher metadata requirements, greater need for standardization of views, higher resolution), a two-tiered system was proposed.  A basic (or "legacy") collection would have more relaxed requirements.  A more demanding full (or "regular") collection would have more stringent requirements and constitute a subset of the basic collection.  When searching the image database, the user will have the choice of more stringency producing fewer hits, or relaxed stringency producing more hits. 

3.  Basic collection

a. Minimum requirements for inclusion in the basic collection:

  • The specimen is accurately identified to species.
  • The image can be categorized into one of the standard views and approximately meets the specifications of that view.
  • The copyright holder (i.e. photographer or institution) is willing to allow use of the image under a license no more restrictive than Creative Commons Attribution-Noncommercial-Share Alike 3.0 (BY-NC-SA).
  • b. Preferences for the basic collection:

  • Images from the same specimen are associated with each other.
  • Text location data (Darwin Core continent, country, stateProvince, county, and locality elements) provided
  • High resolution image of at least 3 megapixels provided
  • 4. Full collection

    a. Minimum requirements for inclusion in the full collection:

  • Images of enough views are taken of the specimen to allow for identification and annotation from the images. Images of the same specimen are associated with each other. The more views taken the better, but we recognize the time limitations of the photographer. The Baskauf and Kirchoff (2008) paper suggests which views are the most important to photograph. The specimen is accurately identified to species.
  • The image can be categorized into one of the standard views and meets the specifications of that view.
  • Location data in the form of decimal latitude and longitude, and as text descriptions must be provided for the specimen. The Darwin Core informationWithheld and dataGeneralizations elements should be used to flag sensitive species for which the GPS data has been reduced in resolution.
  • Date/time information are available for the image
  • The copyright holder (i.e. photographer or institution) is willing to allow use of the image under a license no more restrictive than Creative Commons Attribution-Noncommercial-Share Alike 3.0 (BY-NC-SA).
  • High resolution image of at least 3 megapixels provided.
  • No distracting objects in image and no text added to image. No collages.
  • b. Preferences for the full collection:

  • High resolution image of at least 6 megapixels provided (all new images should be taken with this as a minimum resolution).
  • Background of close-ups black.
  • Distance from object to film plane in mm provided (to establish scale).
  • If the photographer is working in a team collecting physical specimens and the photographed plant is actually collected, the catalog number of the physical specimen should be associated with the images.
  • 5. Indicating the SERNEC Collection status of an image

    The machine-readable metadata (RDF) for an image in the collection should contain the term sernecImageCollectionStatus to indicate the level at which the image meets the requirements listed above.  Images that meet the standards of the basic collection should be given a value of "1" and images that meet the standards of the full collection should be assigned a value of "2".  Images that do not meet the standards of either collection or for which standard views have not yet been assigned should be given a value of "0".  See for an RDF example.

    The human-readable form of the metadata (web page) may include the SERNEC collection status as text or a logo yet to be created.

    6. Other recommendations.  For more detailed information about these recommendations and the rationale behind them, see the full report of the SERNEC Live Plant Imaging subgroup

    References for further information:

  • SERNEC homepage
  • Summary of 2007-08 Discussions of the Live Plant Imaging Subgroup
  • Summary of Creative Commons Licenses