Should you embed alt text inside image metadata?


Screenshot showing technical details of the metadata on a photo. It contains a copyright notice.

Not everyone can see the images you post online. They may have vision problems, they may have a slow connection, or they might be using a text-only browser. How can we let them know what the image shows? The answer is alt text. In HTML we can add a snippet of text to aid accessibility. For example <img src="monalisa.jpg" alt="A painting of the Mona Lisa."> Most social networks will let users add alt text to help describe their images. Brilliant! But... People don't always add alt text when…

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Reducing GPS accuracy in photos


Unix is user-friendly — it's just choosy about who its friends are.

Here's a quick one-liner to reduce the precision of location stored in a photo's EXIF metadata: exiftool -c "%.2f" -TagsFromFile @ -GPSLatitude -GPSLongitude photo.jpg (Thanks to the EXIFtool Forum for their help.) Why is this useful? Modern phones automatically attach a GPS location to every photo you take. GPS resolution is around 10 metres. When you share your photos, you're often sharing your precise location. I wanted to upload some photos to the Wikimedia Commons of an interesting…

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