Sizing an image 1:1 without a scale

Forum|Forum|6 years ago
October 4, 2019
4 replies
1348 views

I receive photos of fingerprints without a scale present and need to 'size' the image 1:1 for searching purposes. How do I do that with the new Adobe Creative Cloud PS?

How to

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Correct answer davescm

Hi

You can use the Measurement Scale and Ruler tool in Image > Analysis to measure elements in the image. But, first you need to have a known measurement in the image from which you can set the scale or you need to know, and manually enter, the scale based on pixels per given unit of length.

If you know the focal length of the lens used, the sensor size and the exact distance to the subject it would be possible to mathematically work out a ppi to give a 100% subject to image relationship, but that is not something Photoshop will work out for you.

Dave

jane-e

Community Expert

Hi ceakinsjr,

Feature requests for Photoshop should be made here for the engineers to see:

https://feedback.photoshop.com/photoshop_family

In the meanwhile, use the method that @davescm gave you earlier.

~ Jane

davescm

Correct answer

Community Expert

Hi

You can use the Measurement Scale and Ruler tool in Image > Analysis to measure elements in the image. But, first you need to have a known measurement in the image from which you can set the scale or you need to know, and manually enter, the scale based on pixels per given unit of length.

If you know the focal length of the lens used, the sensor size and the exact distance to the subject it would be possible to mathematically work out a ppi to give a 100% subject to image relationship, but that is not something Photoshop will work out for you.

Dave

C

ceakinsjrAuthor

Participating Frequently

Hi. Thank you Dave. That is very helpful. I didn't think there was a way without a reference or without it being very difficult. A known measurement in the image is what's never there in these situations, so I will just do the best I can without being able to do that. I wish someone would create a 'sizing filter' like we had for a previous version but I haven't been able to find out. Thanks again!