Media identification
A method and apparatus for identifying a media item. The apparatus includes a module for receiving media items and capturing an image of a received media item. The method involves ascertaining external dimensions of the media item from the captured image; creating a monochromatic image based on high contrast boundaries within the captured image; matching the monochromatic image to one of a plurality of templates of media items of approximately the same external dimensions as the media item; and providing details of the matched template, including type and orientation of the media item corresponding to the matched template.
1. A method of creating a template for identifying a media item, the method comprising:
(a) receiving an image of a media item from an imager while the media item is selectively illuminated with: an upper linear array of green Light Emitting Diodes (LEDs) that illuminates across a long edge of the media item, a lower linear array of green LEDs that illuminates across the long edge of the media item, and a lower linear array of Infrared (IR) LEDs that illuminates across the long edge of the media item, obtaining reflectance measurements from the upper linear array of green LEDs when the lower linear array of green LEDs and the lower linear array of IR LEDs are de-energized, and obtaining a first transmission measurement from the lower linear arrays of green LEDs while the upper linear array of green LEDs and the lower linear array of IR LEDs are de-energized, and obtaining a second transmission measurement from the lower linear array of IR LEDs while the upper linear array of green LEDs and the lower linear array of green LEDs are de-energized;
(b) creating a monochromatic image based on high contrast boundaries
within the received image by 1) identifying from the image four corners of the media item, 2) determining a size of the media item from the image in pixels, surrounded by the four corners, cropping the image by a predetermined amount from the identified corners producing a modified image, and processing a high-pass filter on the modified image for identifying strongest edges within the modified image and creating the monochromatic image as the modified image following processing of the high-pass filter;
(c) repeating steps (a) to (b) for another instance of : 1) a same type of media item as a type of media associated with the media item, 2) in a same orientation as an original orientation that the media item was presented for receiving the image, 3) a same denomination that is associated with the media item, and 4) a same series that is associated with the media item; and
(d) averaging the monochromatic images to create a template for the type of media and the original orientation of the media item and the instance.
2. A method according to claim 1 , wherein the method comprises the further step of (b-1) ascertaining external dimensions of the media item from the received image.
3. A method according to claim 1 , wherein the method comprises the further step of (e) applying a threshold filter to the averaged monochromatic images to create a template with sharp edge boundaries.
4. A general purpose computer programmed to implement all of the steps of claim 1 .