What is camera matching, and how does it work?

23rd September 2016

“Camera matching” is a system used during the enclosing stage of direct mail production to ensure that two or more personalised mail items are enclosed together into the same outer envelope.

The cameras scan each piece and if an error is discovered the enclosing machine stops and asks the operator to correct the error before resuming.

The camera system also serves a dual purpose in checking that 100% of a mailing is being enclosed. The cameras are used to check the sequential number of each pack and if a run isn’t in sequence or an item is missing then the machine will stop and ask the operator to check and correct the error.

The camera system also writes information to a computer log that can be interrogated at a later point to ensure that everything is in order and to identify any packs that may need to be manually checked at the end of the enclosing run.

How does it work?

For a camera system to work effectively it needs 3 things:

  • A Camera for each personalised item (picture above), so two-way matching would require 2 cameras, and two-way with 100% verification would require 3 cameras.
  • A computer to connect to the cameras and do the requisite checks and to send a signal to the enclosing machine in the case of an error.
  • Some form of barcode on the piece(s) for the cameras to read. This is usually in the form of a 2D Data Matrix Barcode (picture below) but can be 3 of 9 Barcodes or OCR readable fonts.

The Technical Part

As can be seen from the image of the barcode above, the cameras capture the image in black and white only. This gives the image a greater amount of contrast to give the software the best chance of analysing the image.

Although the cameras can read a barcode printed in coloured ink, it is recommended to put the barcodes as black or to use a very dark colour when designing mail pieces; this gives the camera matching system the best chance of correctly identifying the barcodes and allows enclosing machines to run at higher speeds.

Once each barcode on each mailing item have been read successfully the computer can compare the values. Running a two-way matching job the system checks that both of the barcode values are identical; for three-way matching jobs, three values would need to be identical.

Producing a large number of items for a direct mail job sometimes results in a small number of items becoming damaged, these are known as spoils and are discarded; customers can however request a job be 100%, which means that every single item will be guaranteed to be produced and mailed successfully.

Camera matching is used to check 100% mailings by logging each barcode on every mailing item, and once all of the mailing items have been scanned software is then used to check if all of the required sequence numbers appear in the camera logs; any missing items can be re-produced and added to the mailing run.