This is what it looks like when graphics cry (blur)

blobblob Member, PRO Posts: 229

I did this by mistake, I thought 1 or 2 here would like to see what we often talk/fuss about, yet with very little actual examples of it:

For those who ever wonder how it looked when an image is not the right size ex: (odd number, not a multiple of 2).
On the left, this is a perfect example of the blurriness, AKA aliasing, you can get when disregarding the "divisible by 4 recommendation", (thank you @Socks :)
Both vertical line were completely sharp before export.
Due to odd sizing, the line on the left ends up in between pixels and so is aliased.
As opposed to the right line, which is the way it should look when an image falls right on a physical pixel.

Comments

  • SocksSocks London, UK.Member Posts: 12,822
    edited August 2016

    @blob said:
    On the left, this is a perfect example of the blurriness, AKA aliasing, you can get when disregarding the 16, 32, 64, 128, 256... rule.

    I think you are conflating two issues, the powers-of-two recommendation (keeping image pixel counts to powers-of-two values / 16, 32, 64, 128, 256 . . and so on) and the unrelated divisible by two/four recommendation.

    The powers-of-two recommendation is to do with memory use and has no effect on image fidelity.
    The divisible by two/four recommendation effects only image fidelity and has no effect on memory use.

    So for example you can ignore the powers-of-two recommendation - and have a 260 x 260 pixel image - and will have no issues with aliasing/blurring.

    @blob said:
    Due to odd sizing, the line on the left ends up in between pixels and so is aliased.

    By the way, you can simply change an odd sized image/actor's coordinates to correct the issue if you don't want to resize your image asset, so for example if you have a 257 x 256 pixel image/actor sitting at x100, y100, you can get the pixels in the image to sit on the pixels on your device - to avoid any aliasing - by changing the x location of the actor from x100 to x99.5.

  • blobblob Member, PRO Posts: 229

    @Socks said:

    @blob said:
    On the left, this is a perfect example of the blurriness, AKA aliasing, you can get when disregarding the 16, 32, 64, 128, 256... rule.

    I think you are conflating two issues, the powers-of-two recommendation (keeping image pixel counts to powers-of-two values / 16, 32, 64, 128, 256 . . and so on) and the unrelated divisible by two/four recommendation.

    Yes, completely unrelated, thanks for pointing this out, I've been working with memory allocation all morning..... i meant odd numbers.

    @blob said:
    Due to odd sizing, the line on the left ends up in between pixels and so is aliased.

    By the way, you can simply change an odd sized image/actor's coordinates to correct the issue

    I can't, this would make the other side blurred.

  • SocksSocks London, UK.Member Posts: 12,822

    @blob said:
    Yes, completely unrelated, thanks for pointing this out, I've been working with memory allocation all morning..... i meant odd numbers.

    Sorry to sound like a pedant :# :) :D this isn't quite right either, an even number can also cause aliasing, for example on Retina iDevices (so pretty much all Apple devices these days), an image that is 142 wide (even) will still alias when applied to an actor at half size (to account for Retina) as 71 is not divisible by 2 . . . which is the reason for the divisible by 4 recommendation rather than simply recommending even number values.

    @blob said:

    By the way, you can simply change an odd sized image/actor's coordinates to correct the issue

    I can't, this would make the other side blurred.

    That's kinda . . . . impossible ! :smiley: You can't have sub pixel dimensions on a pixel based file, so the x pixel count of the image is either even or odd, if it's even you can place it on a whole numbered x coordinate and it won't alias, if it's odd then you can place it on a half (0.5) numbered x coordinate and it won't alias, but you can't have an image that won't work on either.

    Sorry for all the pedantry !

  • blobblob Member, PRO Posts: 229

    @Socks said:

    @blob said:
    Yes, completely unrelated, thanks for pointing this out, I've been working with memory allocation all morning..... i meant odd numbers.

    Sorry to sound like a pedant :# :)

    You don't. I like it.
    It's like a farmer (me) talking to scientist (you) about chicken biology.
    Imagine what we could create together lol...
    You're been more accurate and precise than i was.
    I know what you mean.

    @blob said:

    By the way, you can simply change an odd sized image/actor's coordinates to correct the issue

    I can't, this would make the other side blurred.

    That's kinda . . . . impossible !

    no, I was referring to the image i posted blurry only on 1 side.

  • SocksSocks London, UK.Member Posts: 12,822
    edited August 2016

    @blob said:
    It's like a farmer (me) talking to scientist (you) about chicken biology.
    Imagine what we could create together lol...

    Some kind of giant metal super chicken with powers previously unknown in the poultry farming world !

  • blobblob Member, PRO Posts: 229

    Now the real question:
    Can we still qualify super metal chickens as poultry?
    I'm lobbying congress as we speak!
    If this makes it into a law, imagine all the metal sandwiches we could sell....!!!

Sign In or Register to comment.