Graphical verification code generation method

Abstract

The invention discloses a graphical verification code generation method. The method comprises the following steps: preparing a plurality of character sets; calculating a character width value W, a character height value H, a character left margin L and a character top margin T of each character each character set in the conditions of different font sizes and different formats; selecting a character set from the character sets, and selecting a preset number of characters from the character set to obtain a set S; according to a height of a canvas and a front size configuration scope of the selected character set, determining an output font size; outputting each character in the set S in order on the canvas according to the determined output font size, wherein, when outputting each character, firstly determining a background left margin BL and a background top margin BT of a present output character, then outputting the character on the canvas according to the W, H, L, T, BL, and TL of the character. By utilizing a technical scheme of the present invention, a clear and symmetric verification code is generated, an input error rate of a user is reduced, and pressure of a server is lightened.

Description

technical field [0001] The invention relates to the technical field of Internet applications, in particular to a method for generating graphic verification codes. Background technique [0002] At present, in Internet applications, many websites use graphic verification code technology to prevent users from using robots to automatically register, log in, and flood water. The so-called graphic verification code is to generate a picture with a string of randomly generated numbers or characters. Some noise pixels can also be added to the picture, and the user can identify the verification code information with the naked eye, enter the form and submit it to the website for verification. Only after the verification is successful can the Use a function. [0003] At present, the general method of generating graphic verification codes is: generate a random string, store the string in the memory, display the picture generated by the string to the user, the user identifies the string ...

AI Technical Summary

Problems solved by technology

[0004] However, existing methods for generating graphic verification code output from different character sets, or setting graphic verification code output methods with different font sizes, rotation, bold or italic formats, all have problems such as overlapping characters, blurring, or being large or small. , that is, the generated graphic verification code is relatively rough, which makes it difficult for users to identify, and the probability of input errors is relatively high, causing a lot of unnecessary network traffic and pressure on the server

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