parallax/jsPDF

exif orientation is handled incorrectly

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#3,795 创建于 2024年11月21日

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 (7 评论) (2 反应) (0 负责人)JavaScript (28,280 star) (4,596 fork)batch import
Feature Requesthelp wanted

描述

jspdf handles exif orientation and correctly flips width and height. However, it does not actually rotate the image. Instead it just stretches the unrotated image into its rotated shape.

This issue has been rised twice already but it seems that nobody realized that the image is not correctly rotated

In both issues you can actually see, that albeit the image dimension was rotated, the content was not. I encountered the issue when using svg2pdf.js. You can also see another example in the issue I raised: https://github.com/yWorks/svg2pdf.js/issues/315. The orientation is correct, the content is still unrotated and just stretched

贡献者指南

技术栈
javascript
领域
frontend
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
half day
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
active
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
JavaScriptImage processingEXIF orientation
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
60
研究方向
The fix should be applied in the image processing module of jsPDF, likely in files related to JPEG or image handling (e.g., src/libs/JPEGEncoder.js). The developer should examine how EXIF orientation is currently handled and replace the dimension swap with actual rotation of the image pixel data, using Canvas API or similar. Refer to the linked issues (#2815, #2740) and the svg2pdf.js issue for examples of the incorrect behavior.