通过javascript或其他任何语言访问相机和照片信息？

Question

when an image is taken, information such as;

• Date taken
• Camera
• Lens
• Focal Length
• Exposure
• F Number
• ISO
• Camera make
• Flash(if used or not)
• Exposure Bias etc

is at times written within the image and can actually be retrieved for further usage. a live example is what Google plus does (you can see the screen shot below), if you are a chronic Tumblr fan, you might notice that tumblr is capable of that too. Now, how the do they do it?

Answer 1

This information is available within the photo file as so-called "Exif data". You can learn more about how this works on this Wikipedia page: https://en.wikipedia.org/wiki/Exchangeable_image_file_format

An example implementation in JavaScript is https://github.com/exif-js/exif-js