Character size detection method for document picture

The invention provides a method for detecting the character size of a document picture. Firstly, an original picture of a document is obtained and subjected to image preprocessing; then, character area positioning is carried out; secondly, carrying out secondary segmentation on the obtained character region to obtain an image set of single characters; performing row and column pixel traversal on each image in the single character image set to obtain a pixel value of each character in the original image of the document; then, obtaining a document picture scaling ratio; according to the pixel value of each character in the original picture of the document and the zooming proportion of the document picture, obtaining the pixel value of each character in the picture after the document is zoomed; and finally, obtaining the word size of each character in the picture after the document is zoomed by using the comparison table of the pixel values and the word sizes. According to the method, the detection speed is high