Resize canvas without distorce the image? (solved!)

[amoraleite]

Hey guys! As some of you know I use my Affity package to work with Pixel art. I retired my Photoshop.

I have a doubt. When I change the size of my canvas, it distorts my image, my pixel art. You know, pixel art is something very, very precise. In a larger image I could ignore this noise, but in pixel art it is not possible.

I would like to be able to change my canvas without changing the pixels of the image, is this possible?

I'll give an example to make it clearer. the first image is my pure image, and the second one is with the canvas resize applied. 

Thanks in advance for any help.

Edited May 21, 2024 by amoraleite
solved

[GarryP]

My first question is, why are you resizing pixel art? (Won’t that make it more difficult to edit later?)

My second question is, are you resizing to integer multiples of the original dimensions. (For example, with a 100×200 image, if you aren’t resizing to 200×400, or 300×600, etc. then you will naturally have problems with sub-pixels.)

[Alfred]

19 minutes ago, GarryP said:

if you aren’t resizing to [integer multiples of the original dimensions] then you will naturally have problems with sub-pixels

It looks as though there are already problems with sub-pixels before resizing!

[GarryP]

I hadn’t noticed that.

The OP said that it was a “pure image” which I (foolishly, perhaps) interpreted as being a simple pixel layer where each large square that we can see in the screen-grab was directly mapped to a single pixel but that doesn’t seem to be the case, unless there’s something else going on.

Looks like we need to know more about what the OP has, how they got it to where it is now, and what they are doing with it.

amoraleite: Can you share the original image so we can see what you are working with.

[Pšenda]

11 hours ago, amoraleite said:

When I change the size of my canvas, it distorts my image, my pixel art.

Menu Document, Resize Canvas (without Aspect ratio), not Resize Document?

[amoraleite]

Hey guys!

Firstly:
I never said I wanted to resize the pixel art. I even reread it again to see if I had written something wrong... I use Aseprite to create my pixel art and there I multiply it to the exact size I want.

We are talking about canvas here. You know? That work area where the art stays. In Photoshop, we can resize the canvas without affecting the internal image, the art.

Second, in response to the pixel art issues, what does this have to do with resizing the canvas? But for you to understand, I have multiple arts resized by 500% and repositioned one on top of the other, layers, (I still have to readjust their positions). This art will be printed on paper, not for monitors. When I said pure, I meant not resized within the AP, as I said I do this in another program.

I understand the problem:
When I change the size of the canvas (not the image size or document size) the image moves and it loses its original pixel position. So we have a distortion. To solve it you have to reposition the pixel on the canvas and the problem will go away. But this is counterproductive, since I just want to change the size of the canvas.

[DWright]

Hi @amoraleite,

I have not been able to replicate the issue with the image changing size when the resize canvas option is used, can you please confirm that the background/image layer is selected and which anchor point are you using for the resize.

[amoraleite]

6 minutes ago, DWright said:

Hi @amoraleite,

I have not been able to replicate the issue with the image changing size when the resize canvas option is used, can you please confirm that the background/image layer is selected and which anchor point are you using for the resize.

Hi @DWright! Of course mate! Thanks for trying to reproduce!

No layers selected and my anchor is center: 



I'll show to you two images, one is the original without canvas resize and the other with the canvas resize applied.




One important thing to say, these images will be printed, so I'm having to work with inches.

To solve this I have to position the art on the canvas. There is! Another very important thing, I tried to use the force feature to align the pixels and move the whole pixel too... not work for me. 

But when I move the image, the strange pixels disappear:

In this case I only moved the ship, the scenery and the other things I didn't move, see how the strange pixels on the ship disappeared when I moved the image. I'm going to make a video about this.
 

[Pšenda]

38 minutes ago, amoraleite said:

But when I move the image

The problem is that you have the anchor placed in the middle. For pixel perfect, I would use the top left anchor.

39 minutes ago, amoraleite said:

One important thing to say, these images will be printed, so I'm having to work with inches.

Checking the exact (integer) pixel/image position in inches is impossible. Therefore for pixel perfect, I would always work in pixels, and only for printing and checking the size would I switch to inches.

[MEB]

20 minutes ago, Pšenda said:

The problem is that you have the anchor placed in the middle. For pixel perfect, I would use the top left anchor.

Checking the exact (integer) pixel/image position in inches is impossible. Therefore for pixel perfect, I would always work in pixels, and only for printing and checking the size would I switch to inches.

He can still use the anchor placed in the middle but may have to move the layer slightly to force its alignment with the pixel grid.
Keeping the top left anchor makes things a bit easier.

The process goes like this:
- go to menu Document > Resize Canvas
- set the anchor to middle
- set the dimensions you want in inches or cm (click the other field to update the value proportionately)
- still in the same dialog after inserting the dimensions in inches or cm change the units to pixels
- remove the link between width and heigh fields (so you can round one of the values without affecting the other)
- remove the decimal parts from the pixel values
- click Resize buton

With the anchor set to the middle, the output may be misaligned. To fix it make sure Force Pixel Alignment is turned ON (and Move By Whole Pixels turned OFF) and with the Move Tool move the layer/object on canvas a bit until it aligns with the pixel grid. It should become sharp again.

[amoraleite]

@Pšenda Worked! When I placed the anchor top left corner. But unfortunately I need gain area on the all sides of my canvas. But you workaround work for me, I have to move all the layer to the center... 

6 minutes ago, Pšenda said:

Checking the exact (integer) pixel/image position in inches is impossible. Therefore for pixel perfect, I would always work in pixels, and only for printing and checking the size would I switch to inches.

This is exactly what I doing. I work on Aseprite. AP is just for print : ) But sometimes we need to adjust the canvas or reposition an image, in this case I have all the art in layers so I can replace and move these images easily.

[Old Bruce]

4 hours ago, amoraleite said:

No layers selected and my anchor is center: 

I would use Pixels as a unit of measure instead of cm. The metric system doesn't work well with Pixels and Pixels per Inch.

[debraspicher]

This is why I keep around a graphing calculator... Tables function helps so much for finding whole numbers with setting up my own grids.

Like @Old Bruce has mentioned, you idealy should setup your units to PIXELS and do the math on your end for your final resolution (300 pixels per inch, etc)... this makes the Canvas feature work as you intend, because it's going to chop edges pixel by pixel when making changes and not force you to work around unworkable unit for your design.

Edit: If you need Inches in your final, you can always change it once everything is nice and snug on a grid and make sure it does not rescale... you would have to put in the DPI you calculated for (obviously). You can also setup a different file for File->Place perhaps and maybe that might work well... provided bugs don't happen. I always just use a file-naming convention such as "_DATE_PROJECTNUMBER_blah-art_6x6@XXXDPI"... and just keep things in pixel...

[amoraleite]

Guys thank you, but my doubt was solved. 😃 @MEB @Pšenda Thank you for clarify and help with the workaround. 
 

[debraspicher]

6 minutes ago, amoraleite said:

Guys thank you, but my doubt was solved. 😃 @MEB @Pšenda Thank you for clarify and help with the workaround.

Sometimes it's best to keep multiple solutions in the same thread for other members who look these issues up in search. They will pick whatever fits best for their own needs. Many of us are interested in pixel-sharp clarity, but may have other workflows that often result in a similar problem. So it could help them to avoid the problem at time of document setup depending on when they encountered the issue.

[amoraleite]

I agree. But your answer is outside of my question. Sorry, but I asked about changing the canvas size and an issue with the position of the art on this canvas. I think your answer concerns resizing. Please read what I wrote above. But thanks anyway.

[debraspicher]

50 minutes ago, amoraleite said:

I agree. But your answer is outside of my question. Sorry, but I asked about changing the canvas size and an issue with the position of the art on this canvas. I think your answer concerns resizing. Please read what I wrote above. But thanks anyway.

It's fine. I'm aware you were talking about Canvas. Take care.