The present invention concerns an optical reading apparatus and an optical reading method for obtaining objective information by reading a subject and processing the read information through an arithmetic processing. The optical reading apparatus includes a light source to irradiate a light flux onto a subject; a photo-receiving element to receive a reflected light or a transmitted light of the light flux irradiated onto the subject, and to generate signals based on an opt-electronic converting action; an arithmetic processing section to apply an arithmetic processing to the signals, in order to detect information of the subject; and a calculating section to apply a calculating processing, for reducing noise components caused by optical factors, to the signals generated by the photo-receiving element, in order to obtain output signals in which noise components are reduced, before the arithmetic processing section applies the arithmetic processing to the signals.

An optical code reader system is provided for reading a presented optical code having first and second sets of elements, the first set of elements including a plurality of elements having a first reflective property and the second set of elements including a plurality of elements having a second reflective property. The system includes a photo sensor module which senses incident light reflected from the presented optical code and generates electrical signals corresponding to the sensing. The system further includes a software decoder module executable on a processor for uncompensating the presented optical code by adjusting a relative measured dimension of individual elements of the first set of elements in accordance with a predetermined adjustment factor for uncompensating the first set of elements without uncompensating the second set of elements for generating an uncompensated optical code.

Techniques for removing noise effects in processing a barcode signal. A photosignal produced by scanning a barcode is used to generate a digital first derivative signal. Positive and negative thresholds are generated based on the digital first derivative signal. Processing windows are defined for each region of the first derivative signal which exceeds a threshold. Each processing window is bounded by a window opening point at which the first derivative signal exceeds a threshold, and by a window closing point, which is the last crossing of the threshold by the first derivative signal before the first derivative signal makes a zero crossing. Each region is processed to locate a geometric center of the region. A logic transition is recognized for the geometric center of each region defined by a processing window.

A method for producing an ink-spread compensated variant of an existing optical code encodation scheme, wherein the existing encodation scheme has printed areas and spaces having a length in at least one dimension being a function of a given unit length for encoding information. In the method, the pattern of printed areas and spaces for a given data input is determined and a given length is added to the length of each space while the length of the printed areas remains unchanged to enlarge the overall length of the resulting code symbol in the at least one dimension.

A method for producing an ink-spread compensated variant of an existing optical code encodation scheme, wherein the existing encodation scheme has printed areas and spaces having a length in at least one dimension being a function of a given unit length for encoding information. In the method, the pattern of printed areas and spaces for a given data input is determined and a given length is added to the length of each space while the length of the printed areas remains unchanged to enlarge the overall length of the resulting code symbol in the at least one dimension.