deanwagner's profile

2 Messages

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132 Points

Thu, Mar 18, 2021 4:48 PM

Closed

Lightroom Classic: Is there a way to control the resolution of embedded EXIF thumbnails within images?

I'm writing an image gallery script for my website portfolio and would like to make use of the embedded EXIF thumbnails within my images rather than having to create and manage separate thumbnail images. I can successfully extract and display the embedded EXIF thumbnails but they are much smaller than I would like them to be. I've noticed that they change sizes depending on the size of the original. For example, a 1920x1280 image will yield a 160x107 thumbnail, whereas a 5959x3973 image will have a 256x171 thumbnail.


I was hoping that there is some way to explicitly define the EXIF thumbnail size and/or ratio relative to the original image so that when I export my images from Lightroom they will have larger thumbnails embedded into the EXIF metadata.

Here's a screen shot of what I'm able to extract from the image files:

Accepted Solution

Champion

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6K Messages

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103.7K Points

8 m ago

There's no way in LR to control the size of the embedded thumbnails. 

I think you could write an Export post-processing action script that uses, say, ImageMagick to create a larger thumbnail and then invokes Exiftool to store the thumbnail in the exported image.

But note that the base EXIF standard limits the thumbnails to a maximum 64 KB. There are extensions to the standard allowing larger thumbnails, but not all programs implement those extensions:

https://en.wikipedia.org/wiki/Exif#Technical_2 

2 Messages

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132 Points

Thanks for the info! I wasn't aware of the size limitation, especially considering that bigger images have bigger thumbnails. I may have picked up on it if that weren't the case. I do like your suggestions, but I think I'll just create the thumbnails on-the-fly in my gallery whenever they're first accessed by a user and store them in a cache on the server.