resizing image removes elements

[drawflies]

Whether just dealing w/ a png file (resizing) like attached, or converting to smaller sized icon, for the most part it eliminates the white circle, when reduce to somewhere around 32 x 32 px.

 

Maybe this is because the reduction makes the given element too small to reproduce?

 

But, in the reduced versions, there are PARTS of the white line that are clearly visible - but not a solid white line.  So if it shows part of the line, as an intermittently dashed line, why can't it show the entire line?

 

The image was created  /  saved at 32 bits.  It's not only a problem dealing w/ icons - it's reducing png files as well.

 

I'm thinking it may be better to start off w/ an image close to the finished size.  But w/ icons in one icon file ranging from 16 to 64 & even 256 px, that's hard to do.

 

Thanks.

Edited May 22, 2013 by drawflies

[pdnnoob]

Maybe this is because the reduction makes the given element too small to reproduce?

Exactly. Your white line is one pixel thick, so making the image smaller requires your computer to reproduce the white line...with less than one pixel of thickness? Doesn't work out too well. It still tries, though--hence the dotted white line.

It's not that the program "shows" the white line. It doesn't "know" there is a white line to begin with, so it doesn't know to complete the white line after resizing.

It isn't uncommon to have this problem when resizing icons. For example, Firefox has multiple "versions" of its icon because it had to be tweaked to look right at each size. If you directly shrunk the logo from the large version to the little 16x16 size, you wouldn't be able to make out the details at all. Someone had to go in and edit it after the resize to make sure the important features showed up properly (vector art isn't perfect either).

All that to say, my suggestion to you is to simply draw a white circle back in after you shrink the image.

[drawflies]

"The water's cold - there's a lot of shrinkage."... George Costanza.

 

Yes, I see that scaling it down (at least not in these programs - PDN, Greenfish, etc.) don't produce an exact, smaller duplicate.  Obviously,the resampling doesn't help when it gets to these small of sizes of elements - dividing 1 px wide element by 4.

 

What about in a case like this, starting w/ the 16 or 32 px size, design it & then enlarge.  Short of editing each size, seems it'd work much better enlarging small elements than shrinking them.

[pdnnoob]

When you scale up an image, the program has to extrapolate data because there isn't as much image data available to fill the large image (click here for a more detailed explanation). For this reason, it is generally preferred to work large and shrink than work small and enlarge.

EDIT: Fixed link. Sections 3 and 4 are what I wanted to link to, but apparently that doesn't work

[drawflies]

Thanks.  I see that shrinking doesn't work well on detailed images, w/ elements that start getting divided into fractions of one px.  Of course, elements could be drawn large enough on the original to allow shrinking & not have fractions of 1 px.

 

It's weird - when click or copy / paste the link you gave, the page flashes quickly, then get a "sorry, page not found."  But, I searched for the thread # & found it that way.

 

I'll have to try starting w/ a small size (when 1 or 2 px wide elements are involved) & enlarge to see how that works.  Otherwise, I'll just be duplicating each layer process for each image size.  Sure, if I was Mozilla, it'd be well worth the time.

[pdnnoob]

Fixed the link. Again, I don't recommend working small and enlarging after, but if that works out better for you, there isn't a rule against it

[Ego Eram Reputo]

The best solution is to start with a canvas size twice as large and twice as high as your final image (insert arguments here for 4x or even 8x size).  When you resize, an even number of pixels is sampled to create the resultant pixel.

 

Of course in your 2x (4x, 8x) image, you'll need to make the white line 2x the final thickness.  This system ensures the elements scale well when reduced by 1/2 (1/4, 1/8).

 

As 'Noob mentioned, it is common to have to tweak images once they have been scaled smaller.