Problem of semi-transparents pixels in Photoshop

[Helene-Charlotte13]

good evening,

i would like to know if, in Photoshop, there is a way to prevent the pixels forming the external outline of an image from becoming semi-transparent when you change the size of the image?
in advance, I thank you for your answer,
cordially,
Hélène.

[Claire H.]

Hi @Helene-Charlotte13, Can you please share screenshot examples of the issue you're experiencing? Thanks! ^CH

[Helene-Charlotte13]

Thank you for your response Claire,

Yes of course, here is some screenshot examples of the problem.This happens systematically when changing the size of the image, the pixel band which borders the image becomes semi-transparent. This is very annoying for me, because I work on patterns which must be repeated indefinitely and I have to modify their dimensions on several occasions, in particular to be able to present them in lower definitions to my clients, the band of pixels around the edge of the image connection appears as a repetition defect. how can I prevent this from happening?
it happens with the original image as well as the image colored by layers.
Hope you can help me?
in advance, thank you.
Hélène.

[Trevor.Dennis]

Is this to do with a mask?   

Are you using Quick Mask perhaps?  (does  part of the image have a pink tint?).

Or are you using the new Selection brush (majenta tint).

If you take Claire's advise and show us a screen shot, it would make things clearer.  Make it of the entire workspace at full resolution, with the layers, and Channel panels showing and the layer selected that is causing the issue.

Thanks

[Helene-Charlotte13]

Thank you for your response Trevor,

Yes of course, here is some screenshot examples of the problem.This happens systematically when changing the size of the image, the pixel band which borders the image becomes semi-transparent. This is very annoying for me, because I work on patterns which must be repeated indefinitely and I have to modify their dimensions on several occasions, in particular to be able to present them in lower definitions to my clients, the band of pixels around the edge of the image connection appears as a repetition defect. how can I prevent this from happening?
it happens with the original image as well as the image colored by layers.
Hope you can help me?
in advance, thank you.
Hélène.

[Semaphoric]

This has been the case for years. You can avoid it by temporarily changing the resampling to Nearest Neighbor. 

[Helene-Charlotte13]

Thank you for your response, Semaphoric.

I don't understand what do you mean exactly about " changing the resampling to nearest neighbor"?

would you explain to me what to do?

[D Fosse]

This happens with floating layers, but not a flat Background layer:

I've known about this "forever", so I've always been careful when resizing layered files. Take your precautions, and this shouldn't be a big problem.

I presume the explanation is that floating layers support content outside the canvas boundary, but a background does not.