diff options
| -rw-r--r-- | app/javascript/mastodon/utils/resize_image.js | 45 |
1 files changed, 44 insertions, 1 deletions
diff --git a/app/javascript/mastodon/utils/resize_image.js b/app/javascript/mastodon/utils/resize_image.js index 7196dc96b..710a08f7c 100644 --- a/app/javascript/mastodon/utils/resize_image.js +++ b/app/javascript/mastodon/utils/resize_image.js @@ -2,6 +2,45 @@ import EXIF from 'exif-js'; const MAX_IMAGE_PIXELS = 1638400; // 1280x1280px +const _browser_quirks = {}; + +// Some browsers will automatically draw images respecting their EXIF orientation +// while others won't, and the safest way to detect that is to examine how it +// is done on a known image. +// See https://github.com/w3c/csswg-drafts/issues/4666 +// and https://github.com/blueimp/JavaScript-Load-Image/commit/1e4df707821a0afcc11ea0720ee403b8759f3881 +const dropOrientationIfNeeded = (orientation) => new Promise(resolve => { + switch (_browser_quirks['image-orientation-automatic']) { + case true: + resolve(1); + break; + case false: + resolve(orientation); + break; + default: + // black 2x1 JPEG, with the following meta information set: + // - EXIF Orientation: 6 (Rotated 90° CCW) + const testImageURL = + 'data:image/jpeg;base64,/9j/4QAiRXhpZgAATU0AKgAAAAgAAQESAAMAAAABAAYAAAA' + + 'AAAD/2wCEAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBA' + + 'QEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQE' + + 'BAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAf/AABEIAAEAAgMBEQACEQEDEQH/x' + + 'ABKAAEAAAAAAAAAAAAAAAAAAAALEAEAAAAAAAAAAAAAAAAAAAAAAQEAAAAAAAAAAAAAAAA' + + 'AAAAAEQEAAAAAAAAAAAAAAAAAAAAA/9oADAMBAAIRAxEAPwA/8H//2Q=='; + const img = new Image(); + img.onload = () => { + const automatic = (img.width === 1 && img.height === 2); + _browser_quirks['image-orientation-automatic'] = automatic; + resolve(automatic ? 1 : orientation); + }; + img.onerror = () => { + _browser_quirks['image-orientation-automatic'] = false; + resolve(orientation); + }; + img.src = testImageURL; + } +}); + const getImageUrl = inputFile => new Promise((resolve, reject) => { if (window.URL && URL.createObjectURL) { try { @@ -38,7 +77,11 @@ const getOrientation = (img, type = 'image/png') => new Promise(resolve => { EXIF.getData(img, () => { const orientation = EXIF.getTag(img, 'Orientation'); - resolve(orientation); + if (orientation !== 1) { + dropOrientationIfNeeded(orientation).then(resolve).catch(() => resolve(orientation)); + } else { + resolve(orientation); + } }); }); |