METHOD OF SCANNING LARGE-FORMAT DOCUMENT WITH AUTOMATIC DYNAMIC SCALE CORRECTION

摘要

The invention relates to a method for scanning large-format scan templates (4) with an automatic dynamic scale correction function during the scanning process by means of a scanner (1) which has image capturing elements (2) arranged in a cascading manner in order to scan the scan template (4), wherein image information of adjacent sensor elements (11 to 14) is assembled by means of a stitching method and shift values (Vn) are ascertained in said elements. The method has the following steps: S1: deriving shift values (V) for each image line of the assembled image by interpolating the y direction components of the n shift values (Vn), S2: comparing the shift values (V) with a target value (S) in order to determine a relative deviation for each image line and adding the relative deviations until the sum has reached a value which corresponds to the smallest possible error correction for scaling the image information, and S3: scaling the image information or image signals by taking on the value for the error correction.

主权项

1. A method of scanning large-format documents with automatic dynamic scale correction function during the scanning process by a scanner that has image-capturing elements that scan the document, the image-capturing elements each being formed of upstream and downstream sensor elements spaced longitudinally in a document-travel direction in a cascade with at least one area of transverse overlap so that image information from the at least one area of overlap between the sensor elements can be assembled by a stitching method, the at least one area of overlap being scanned for image information within a search area and shift values in both the longitudinal and transverse directions being determined by comparing congruent image information, with the following steps:
S1) deriving shift values for each image line in the compiled image by interpolation of transverse components of n shift values, S2) comparing the shift values with a set point in order to determine a relative deviation for each image line and addition of the relative deviations until their sum has reached a value that corresponds to the smallest possible error correction for scaling of the image information, and S3) scaling the image information or image signals by acceptance of the value for error correction.