Don't let prepress workflows slow you down! Our self-developed tools boost efficiency by nearly 10 times
Development background: Originating from actual production needs
The pre press document processing for digital printing takes up too much time. After communicating with frontline operators, three core requirements have been identified and confirmed.
(1) Batch checking document page numbers: In printing and typesetting, it is often necessary to ensure that the document page numbers are even, otherwise it may lead to waste of printing materials or binding errors.
(2) Automatically process odd page documents: For documents with odd pages, a blank page should be uniformly added at the end, while documents with even pages should remain unchanged.
(3) Batch check for text inflection: To avoid printing errors caused by missing fonts, it is necessary to confirm whether the text in the document has been converted into curves (i.e. "inflection").
Through research on Adobe Acrobat and various PDF processing plugins on the market, it was found that existing tools either have redundant and complex functions, or do not match the actual production process of the company, especially in terms of security risks in converting files. More importantly, domestically produced similar tools often require payment, resulting in higher long-term usage costs. Based on the aforementioned practical issues, the company has decided to develop a lightweight, precise, and internally compatible specialized tool.
PDF Page Checking and Processing Tool
01
Core functions and judgment logic
The core goal of this tool is to ensure that all pages of the document to be printed are even, and its judgment and execution approach is as follows.
(1) Page detection mechanism: Read the metadata of PDF documents through the PyMuPDF library to directly obtain the total page information.
(2) Parity judgment logic: Use modulo operation (page number% 2) to determine parity. If the result is 1, it is judged as an odd page, and if the result is 0, it is judged as an even page.
(3) Differentiation processing strategy: If it is an odd numbered document, automatically add a blank page of the same size as the original document at the end of the document; If it is an even page document, keep the content unchanged and copy it directly to the output directory.
(4) Security processing principle: All processed documents are saved to the designated "processed files" directory, and the original files remain unchanged to avoid file damage caused by misoperation, as shown in Figure 1.
02
Key points of technical implementation
The tool uses Tkinter to build a graphical interface, which mainly includes three functional modules.
(1) Directory selection module: supports visual selection of source file directories and output directories, with the default output directory being a subfolders under the source directory.
(2) Batch processing module: using multi-threaded technology to implement backend processing, avoiding interface lag, and displaying processing progress in real-time through a progress bar.
(3) Result display module: Present the processing results of each file in a table format, including the original page number, processing actions, and status information, and distinguish between successful and failed states by color.
PDF Conversion Check Tool
01
Core functions and judgment logic
The curve checking tool focuses on determining whether the text in the document has been converted into a curve, and its core judgment logic is based on the analysis of font information in PDF documents.
(1) Text presence detection: By using the page text extraction function, determine whether the document contains editable text.
(2) Font information analysis: Analyze the list of embedded fonts in the document. If there is font information, it indicates that the text has not been converted.
(3) Comprehensive judgment rule: If there is text content but no font information, it indicates that the song has been converted (marked in green); No text content, indicating no need to switch tracks (green label); If there is text content and font information, it indicates that the song has not been converted (marked in red), as shown in Figure 2.
The tool is specially designed for the "only check without conversion" mode, mainly because according to feedback from operators, when performing the conversion operation on files containing official seals, it is easy to cause the loss of official seals and other patterns. Therefore, only the check function is retained.
02
Key points of technical implementation
This tool also uses Tkinter to build the interface, and the key technical points include the following three points.
(1) Font information extraction: Using PyMuPDF's text block analysis function, obtain the names and occurrences of all fonts used in the document.
(2) Result visualization: Use a tree view to display the inspection results, and visually distinguish different states through colors and icons.
(3) Status statistics function: Automatically calculate the number of files that meet the requirements, helping operators quickly grasp the overall inspection situation.
Difficulties and Solutions in the Development Process
As a non professional developer, I have encountered many technical challenges during the tool development process. The specific problems and solutions are as follows.
(1) PDF parsing depth issue: The initial PDF library used was unable to accurately extract font information. After AI's recommendation, it was resolved by replacing it with the PyMuPDF library.
(2) Interface lag problem: When processing a large number of files in bulk, the interface is prone to unresponsive states. With the guidance of AI, a multi-threaded processing solution has been implemented to effectively solve this problem.
(3) Chinese display garbled characters: By configuring font parameters and encoding settings, the problem of Chinese display garbled characters in the interface and exported files has been solved.
(4) Exception handling mechanism: In response to the problem of program crashes caused by damaged PDF files, an exception capture mechanism has been improved to ensure that the failure of individual file processing does not affect the overall process.
Throughout the development process, AI tools played an important role as technical consultants, providing not only key code examples but also explaining the principles of PDF file format parsing, helping developers quickly understand professional domain knowledge.
The Value and Prospect of Tool Application
The application of these two tools has brought significant efficiency improvements to production work, which are reflected in the following two aspects.
(1) Time cost savings: The manual inspection work that originally required 1 hour can now be completed in 5 minutes, increasing efficiency by nearly 10 times.
(2) Improved quality stability: effectively avoiding manual inspection omissions and ensuring stable printing quality.
Recording the development process of these two small tools aims to convey the work philosophy of "exploration and innovation", focus on solving specific problems in actual production, optimize traditional workflows through technological means, and ultimately achieve the goal of cost reduction and efficiency improvement.