Profile Determination of Threshold for Bar Code Recognition
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
A bar code reader is shown in the figure for reading a code 2 which includes marks of two lengths, 1/2 high and 1/6 high, which are located in defined regions of a six-region transverse field 7. The location and size of each mark is determined by counting the image pels in each region. The regions are determined to contain a mark where the count of image pels in the region exceeds one-half the count for an adjacent region. A problem in reading these pels is that if they are slanted or tilted, the reader has difficulty in differentiating between the slant and stray marks. Since 1/2 high bars tend to be more slanted than 1/6 high bars, the reader most often misreads the former bars.