parallax/jsPDF

exif orientation is handled incorrectly

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#3,795 opened on 2024年11月21日

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 (7 comments) (2 reactions) (0 assignees)JavaScript (28,280 stars) (4,596 forks)batch import
Feature Requesthelp wanted

説明

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

コントリビューターガイド

技術スタック
javascript
領域
frontend
Issue 種別
bug
難度新しい貢献者にとっての実装難度です。1 は非常に小さな変更、5 は専門的な作業です。
3
推定時間経験ある貢献者が調査、実装、テスト、pull request 準備にかけるおおよその時間範囲です。
half day
活動状況Issue が今どれだけ取り組みやすいかを示します。新しい、活発、古い、ブロック中、またはメンテナー入力待ちなどです。
active
明確さ期待される変更、受け入れ条件、次の手順がどれだけ明確かを示します。
clear
前提条件
JavaScriptImage processingEXIF orientation
初心者向け度初回貢献者にどれだけ取り組みやすいかを 1-100 で推定したスコアです。
60
調査方針
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.