[whatwg] Add EXIF metadata support in Canvas.toBlob?

Jonas Sicking jonas at sicking.cc
Thu Jun 13 20:45:08 PDT 2013

On Thu, Jun 13, 2013 at 8:06 PM, Mark Callow <callow.mark at artspark.co.jp> wrote:
> On 2013/06/08 5:42, David Flanagan wrote:
> [A related, but perhaps too ambitious, proposal is to allow direct
> read/write access to EXIF metadata via HTMLImageElement.  The primary use
> case for read access is to enable web apps to trivially determine when,
> where, and how a photo was taken and also to determine authorship and
> copyright information for an image.  The primary use case for write access
> might be for selectively stripping metadata. It would be nice to be able to
> protect user privacy with code as simple as |delete
> image.metadata.geolocation| for example.]
> I enthusiastically second this. I think the primary use case is to make it
> trivial for JS to be able to orient an image according to its EXIF
> orientation when displaying it on the page. And this use case is huge. The
> vast majority of cameras today tag images with the camera's orientation when
> a picture is made.  Today you have the following choices in order to have
> the image displayed correctly:
> create a copy of the image rotated to a top-left orientation
> manually apply a CSS style that rotates the image according to its specific
> orientation
> A hack using BinaryBlobs, extensive knowledge of the EXIF metadata format
> and I don't know what else.
> None are appealing.

Wouldn't an even better solution be to make browsers support that EXIF
metadata and simply render the image correctly without any action from
the page? At least assuming that the EXIF metadata for orientation is
standardized and implemented consistently between cameras?

/ Jonas

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