We have just fixed two major display bugs that have been plaguing the annotation tool for a while.

Zoom-in issue

In the annotation tool, when you zoomed in far enough (generally 5 times or more, but could vary slightly), the image would start to appear squashed horizontally. This caused the points to appear to be overlaid on the wrong parts of the image, because the image was moving out from under the points, so to speak.

If you zoomed in far enough on the right side of the image pane, you could even see points floating over the gray 'background' of the pane, because the image gets squashed into the left side of the pane and leaves the right side empty.

This issue only affected web browsers that run on the Chromium engine, such as Google Chrome and Microsoft Edge (but not Mozilla Firefox or Safari). It was first reported on September 2019 - twice - but it would have been possible to see the issue as early as July 30, 2019.

Image orientation issue

Some photo files have a piece of metadata which tells the display software (web browser, desktop image viewer, etc.) which direction to orient the photo. This piece of metadata is known as EXIF orientation.

If an image specified an EXIF orientation value, the image would be rotated accordingly in the annotation tool, but the points would stay in their un-rotated positions. This meant the points weren't overlaid over the correct parts of the image. Also, if the rotation was 90 degrees, the image could get stuck on the left side of the image pane and leave blank gray space on the right side.

This issue started off only affecting certain browsers, but eventually ended up in all modern browsers including Mozilla Firefox. It was first reported on April 20, 2020, but could have been seen as early as March 24 in Apple's Safari browser, and April 7 in Chrome or Edge. Starting June 2, Firefox was affected as well.

Status and next steps

Both bugs have been fixed as of June 12, and it should now be safe to use any modern web browser for the annotation tool, including Chrome, Firefox, Safari, and Edge. If you think you still see an issue, please let us know.

If you previously used the annotation tool with either of these bugs present, the bugs could have misled you into annotating the wrong parts of the image. We are currently assessing which sources and images may have been affected, based on the dates that the bugs were present, and we will let source owners know which images those are so they can be double-checked for accuracy.

We apologize for not addressing these bugs sooner. We misjudged the nature of the bugs and how difficult they would be to fix (confusing at first, but simple enough to fix), and we should have prioritized data-accuracy concerns like this anyway. So this has been a learning experience. Thanks for your understanding, and we'll get to work on assessing the affected images.

You can discuss this article on the forum: https://groups.google.com/forum/#!topic/coralnet-users/4WHtsOE6EQw