Measuring character and stroke sizes and spacings for an image

Abstract

A processor measures size or spacing of connected components for an image of text by obtaining a distribution of measurements of distances between edges of connected components. The distances are measured along lines extending in a measuring direction, such as a direction parallel or perpendicular to lines of text, which can be determined based on a measurement of skew. The distance measurements then can be used to produce a distribution of measurements as a function of distance, such as a histogram. Sufficient distances are measured that the histogram or other distribution data indicates a measure of size or spacing of connected components for the image, such as a stroke width, a maximum character width or height, or a spacing between characters, words, or lines. To measure sizes, distance can be measured across pixels within connected components. To measure spacings, distance can be measured across pixels that are not within connected components. Measurements in a direction parallel to lines of text can indicate intercharacter spacing, interword spacing, vertical stroke width, and maximum character width. Measurements in a direction perpendicular to lines of text can indicate interline spacing, horizontal stroke width, and maximum character height. A machine could store an input image in memory, obtain data indicating size or spacing of connected components, modify the stored data according to the sizes or spacings indicated, and provide an output image based on the modification. The data indicating size or spacing could be used in segmentation and character recognition.