Method for adding watermark to PDF file based on JavaScript

Abstract

The invention discloses a method for adding a watermark to a PDF (Portable Document Format) file based on JavaScript, which comprises the following implementation steps of: establishing a file uploading area on a front-end page, and enabling a user to select the PDF file to be added with the watermark and upload the PDF file to a server side; after a user uploads the PDF file to a server side, the file is received and processed by a JavaScript processing module, and a new PDF document is generated according to a processed result; the watermark setting module allows a user to select a watermark type in the newly-built PDF document and set parameters of the watermark; and the JavaScript processing module is used for embedding corresponding information into the newly generated PDF document according to the watermark type and parameters set by the user. According to the method for adding the watermarks to the PDF file based on the JavaScript, multiple types of watermarks including text watermarks and image watermarks can be efficiently and flexibly added to the PDF file in the Web environment, and a user can customize the styles, the positions and the transparency of the watermarks.

Description

Technical Field

[0001] The present invention relates to the technical field of methods for adding watermarks to files, and in particular to a method for adding watermarks to PDF files based on JavaScript. Background Art

[0002] JavaScript (JS for short) is a high-level, interpreted programming language that is widely used in Web development. It is one of the core technologies of Web pages and is usually used together with HTML and CSS to form the basis of modern Web applications.

[0003] XMLHttpRequest (XHR) is a JavaScript object used to make asynchronous requests between a client and a server. It allows web pages to exchange data with a server without reloading the entire page, thereby dynamically updating content. Although there is "XML" in the name, XMLHttpRequest can actually handle data in a variety of formats, including JSON, HTML, text, etc.

[0004] Canvas is a powerful tool provided by HTML5 for drawing graphics on web pages. <canvas>Elements are implemented, allowing developers to dynamically draw images, graphics, and text using JavaScript. Canvas is particularly suitable for applications that require real-time drawing, such as games, data visualization, animation, image processing, etc.

[0005] With the widespread use of electronic documents, PDF files have become an important format for information transmission. However, the existing technology has many shortcomings when adding watermarks to PDF files. For example, most existing tools need to be run in a desktop environment, which is complicated and not flexible enough; at the same time, some tools do not support the PDF format well, resulting in unsatisfactory watermark effects.

[0006] Currently, many JavaScript-based PDF processing libraries (such as PDF.js, jsPDF, etc.) are relatively basic in terms of watermarking functions and cannot meet complex watermarking requirements. For example, they may only support simple text watermarks, but not image watermarks or diverse watermark styles (such as transparency, rotation angle, etc.).

[0007] To this end, in response to the above problems, a method for adding watermarks to PDF files based on JavaScript is designed to better meet actual usage needs. Summary of the invention

[0008] The purpose of the present invention is to provide a method for adding watermarks to PDF files based on JavaScript to solve the problems raised in the above background technology.

[0009] To achieve the above purpose, the present invention provides the following technical solution: a method for adding watermarks to PDF files based on JavaScript, and the implementation steps are as follows:

[0010] Create a file upload area on the front-end page to allow users to select the PDF file to be watermarked and upload it to the server;

[0011] When the user uploads the PDF file to the server, the JavaScript processing module receives and processes the file and generates a new PDF document with the processed result;

[0012] The watermark setting module allows users to select the watermark type and set the watermark parameters in the newly created PDF document;

[0013] The JavaScript processing module embeds the corresponding information into the newly generated PDF document according to the watermark type and parameters set by the user;

[0014] The processed new PDF document with watermark is returned to the user, completing the entire document generation process.

[0015] As a preferred embodiment of the above technical solution, the watermark type is text or image.

[0016] As a preferred embodiment of the above technical solution, the parameters for setting the watermark include the position, transparency and rotation angle of the watermark.

[0017] As a preferred embodiment of the above technical solution, the front-end page includes a file upload area, a watermark setting option and a download button.

[0018] As a preferred embodiment of the above technical solution, the user accesses the front-end page through a browser.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the method for adding watermarks to PDF files based on JavaScript can efficiently and flexibly add various types of watermarks to PDF files in a Web environment, including text and image watermarks, and users can customize the style, position and transparency of the watermark. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention provides a technical solution: a method for adding a watermark to a PDF file based on JavaScript, and the implementation steps are as follows:

[0022] Create a file upload area on the front-end page, so that users can select the PDF file to be watermarked and upload it to the server. Users can find the file upload area on the web page, then select the PDF file on the local computer and click the upload button to upload the file to the server. This file upload area can be a separate form on the web page or the main frame of the entire page;

[0023] When the user uploads the PDF file to the server, the JavaScript processing module receives and processes the file, and generates a new PDF document with the processed result. The processing module can use various technical means, such as image recognition, OCR, etc., to convert the original PDF file into a new PDF document, and feed back the result of the new document to the front-end page. This processing module can be independent or integrated in the JavaScript code;

[0024] The watermark setting module allows the user to select the watermark type and set the parameters of the watermark in the newly created PDF document. The watermark setting module can send instructions to the JavaScript processing module based on the user's selection, telling the processing module how to generate a new document with a watermark. The watermark setting module can provide users with a variety of watermark types to choose from, such as circle, rectangle, ellipse, etc., as well as parameters such as color, font, size, etc. that can be set for the watermark;

[0025] The JavaScript processing module embeds the corresponding information into the newly generated PDF document according to the watermark type and parameters set by the user. The processing module can combine the watermark information set by the user with the generated new PDF document and embed the watermark information into the appropriate position of the document, thereby obtaining a new PDF document with a watermark;

[0026] The processed new PDF document with watermark is returned to the user, and the entire document generation process is completed. After the processing module is completed, the generated new PDF document is returned to the front-end page as a response. After the front-end page receives the response, it can be displayed to the user, completing the entire document generation process.

[0027] In summary, by adding a watermark setting module between the front-end page and the JavaScript processing module, users can easily modify or annotate documents without disclosing the original document. At the same time, since the embedding of watermark information is completed on the server side, the privacy of users can be effectively protected.

[0028] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.< / canvas>

Claims

1. A method for adding watermarks to PDF files based on JavaScript, characterized in that: The implementation steps are as follows: Create a file upload area on the front-end page to allow users to select the PDF file to be watermarked and upload it to the server; When the user uploads the PDF file to the server, the JavaScript processing module receives and processes the file and generates a new PDF document with the processed result; The watermark setting module allows users to select the watermark type and set the watermark parameters in the newly created PDF document; The JavaScript processing module embeds the corresponding information into the newly generated PDF document according to the watermark type and parameters set by the user; The processed new PDF document with watermark is returned to the user, completing the entire document generation process.

2. According to the method of adding watermark to PDF file based on JavaScript in claim 1, it is characterized by: Watermark type is text or image.

3. The method for adding watermarks to PDF files based on JavaScript according to claim 1, characterized in that: The parameters for setting watermarks include the location, transparency and rotation angle of the watermark.

4. The method for adding watermarks to PDF files based on JavaScript according to claim 1, characterized in that: The front-end page contains a file upload area, watermark setting options and a download button.

5. The method for adding watermarks to PDF files based on JavaScript according to claim 1, characterized in that: Users access the front-end page through a browser.