When i resize the image using "Image size", the quality is awful. I tried different options of Resample but none of them matches the image that i had resized last year. I'm using the latest version of Photoshop CC 2017.0.1 (18.0.1) 64-bit. Same problem on Photoshop CC 2015.5.1 (17.0.1 or 20160722.r.156).
This is what i did in July 2016. Better quality and no visible edges. I remember that i did not change anything in image options. Just only resize.
The last working version was CC 2015.5 (17.0 or 20160603.r.88) i guess.
EDIT [moved to correct product forum – moderator]
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With the information posted it is not possible to tell what you are encountering. We would need to see the before and after image image for each of your cases and know the software levels and image size setting used in each image resize operation.
72 pixels is a very small image. Is this what you are starting with, or what you are scaling down to? If this is your starting size, you probably won't be happy with the results no matter what you try.