Avoid anti aliasing when resizing image

[ericosmosNEW]

I was searching through the forum but don‘t seem to get a definite answer to my question.

I’m working with lineart that has completely sharp edges. Whenever I resize (both in Designer and Photo) I get a smoothed out result. Is there any way to avoid this?

Also, moving a selected portion of the lineart around on the same layer (in Photo) results in smoothed out lines.

Any help is greatly appreciated 🙏

[NotMyFault]

There are countless threads covering the topic.

It depends on you actual file size and resize factor, and your intention about resizing- there are many possibilities.

You want to upscale by factor 2, 3, or 4, and get smooth diagonals (but without blurriness)

or do you want to keep the original blockiness, e.g. make every individual pixel x times larger without smoothing diagonals and other lines?
 

Please give us a concrete example document and exact resizing intentions.

Photo or Designer?
resize document, for export, or resize Layer within document?
Having trouble with anti-aliasing?
Having trouble with blurry selections?
 

[ericosmosNEW]

So, for resizing an imported image in Designer I have found a working solution by exporting a tiff file from Photo using the “nearest” option. No smoothing of lines when resizing it in Designer. 👍

But resizing a layer created inside of Photo (e.g. hard lines with the threshold function > flattened) or even just moving a selected portion of that layer results in smoothed line. Here is a clip:

 

[NotMyFault]

Ok, resizing within a document always uses Bilinear Resampling, see:

The basic workaround is to use copy / new from clipboard / Pixel Art resize / copy / paste back. When exporting, use "nearest neighbour".

When moving objects, have snapping active, and "Force Pixel Alignment".

When selecting with Lasso (freehand) tool, check settings:

• anti-aliasing off
• feather 0 px / off

You get more accurate results if converting selections to masks (create mask), and then ensure a hard edge for the mask by PT filter with formula A=step(A,1/2). This ensures selections are 0 or 100%, and nothing in between.

 

To Summarise, you need to ensure all factors are perfectly managed:

1. create hard selections (AA off, feather off)
2. snapping (force pixel alignment, no move by whole pixels)
3. show transfer panel, have 6 digits for pixel
4. Use pixel as unit for documents 
5. Use pixel as unit for lines
6. Use nearest neighbour for Export
7. Use Pixel Art resize
8. use integer factors when resizing layers (but avoid this)
9. use document size with whole integer for x and y
10. activate grid with 1px (or 8px + 8 divisions) 
11. if you resize a layer inside a document, rasterise immediately and check for unwanted blurriness. Undo and correct if required.
12. Never use "merge down", except the lower layer has been rasterised immediately before (or you are sure its perfectly aligned and has document DPI)

This list is probably incomplete

[ericosmosNEW]

😱OMG. I need to hire an assistant to keep track of all these 

But thanks anyway