Wednesday, November 28, 2007

This just in ... Digital Imaging Procedure Updated

Our sources have told us that the UK's Home Office Scientific Development Branch have recently released an update to their 2002 Digital Imaging Procedure.

This new release (58/07) makes some significant revisions. These include a recognition that police services may wish to store their image data on a secure server instead of CD or DVD (write once media) as well as an expansion of the types of available devices for capture and storage of images.

Here are some of the highlights:
  • "It has to be recognised that digital images are not necessarily better than conventional ones (Pg. 5)."
  • "All compression algorithms remove data from the file and some are more effective than others at reconstruction of the data for replay. Generally, the greater the compression ratio, the more seriously affected is the replay (Pg. 6)."
  • "Image processing cannot make up for inadequate data (Pg. 6)."
  • "The generation of the secure copy should be carried out as soon as possible after the capture to reduce the time and opportunity for the accidental or malicious alteration to images (Pg. 16)."
  • "All images should be presented so that evidential content is not compromised. Where possible, images should be presented in their native or original format (Pg. 33)."
  • "It should be understood that images may look different depending on the equipment used. In particular, images viewed on different screens may appear different from one another. An accurate replay facility should be provided wherever possible (Pg. 33)."
  • and ... the flow chart on page 36 is priceless.
All in all, an outstanding piece of work from an agency dedicated to helping make our lives a bit easier. For those who are looking to standardise their procedures and are looking for materials to help, the HOSDB's web site offers a wealth of information.

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