Specimen images are often taken with the camera oriented at a 90° angle, which produces a specimen image that is rotated sideways. In an attempt to produce images that are oriented correctly, one might adjust the camera setting to define the correct orientation, or one might batch rotate the images within file explorer on a PC. These solutions are not ideal because they only modify the EXIF metadata orientation tag within the file and does NOT actually rotate the image file (pixel data). While many software programs (e.g. Chrome, Firefox, MS Windows Explorer, etc) will auto-rotate correctly based on the orientation tag and display the image correctly, not all software programs will do this (e.g. Internet Explorer, some browser plugins, etc). Furthermore, when images are upload on the web, the orientation tags are often not carried over to web derivatives generated by the file upload program (e.g. thumbnail, web views, etc). For example, the image links below will all have the wrong orientation when viewed in Internet Explorer (PC version), and only the full size (original) image will self-orient within Chrome or Firefox.
Web view: https://s.idigbio.org/idigbio-images-prod-webview/d7ce7fda69335db5966a2265e8771e1e.jpg
Full size: https://s.idigbio.org/idigbio-images-prod-fullsize/d7ce7fda69335db5966a2265e8771e1e.jpg
The safest solution is to rotate the actually image data (pixel definition) rather than just the setting the orientation tag. This can be done as a batch processing using image editing programs such as Adobe Lightroom or Photoshop. The link below provides a list of a number of free options for lossless rotation of images. I just download “JPEG Lossless Rotator”, which was easy to use, shows the true rotation of the images within a folder, and provides lossless rotation tools.