Fixed ratio selections not accurate

[77freab]

lol 4.0.6 version still (or again) have this bug. i choose 16:9 and select an area but it selects 1600x894 (and most interesting is that when i change language from english to my native the same actions results in 1600x878).  i find this sooo helpful feature just now and it's not working properly. so sad.

english not native, hope it's good enough.

[Ego Eram Reputo]

This deserves it's own topic. I'll split your post out from the very old thread you posted it in (http://forums.getpaint.net/index.php?/topic/20820-croppig-by-fixed-ratio-is-inexact/page-0)

[Djisves]

PDN 4.06, Win 10, starting with a new 2000*1500 canvas. I just tried several Fixed Ratio and also Fixed Size selections, copying and then pasting into a new image. Everything is working fine on my system. 

 

77freab, are you sure you are not selecting outside the canvas edges? Perhaps you should give it a try on a larger canvas, stay away from the edges and see what happens.

[nadav]

This happens to me as well, when I select outside the canvas edge (4.0.9).

Selecting outside the canvas is the easiest way to ensure I am selecting the "entire" corner.

Photoshop handles outside-canvas by only "counting" the pixels within the image - is there a reason that Paint.net starts the "count" from the starting mouse-position even when outside the canvas?

[Djisves]

This has been PDN normal behaviour as far back as I can remember.

 

To make sure I select edges and/or corners, I use 2 different workarounds:  

 

1a. If I need to select the whole width of an image and part of its height, I use the Rectangle Selection tool and set it to Fixed Size.

I set the selection width to a size larger than the image width and the height to the exact size I need.

I then click just outside the left edge of the image canvas to ensure that the whole width of the image is included in the selection.

 

1b. The same applies of course in case I need to select the whole height and only part of the width.

In this case I set the selection width to the exact size I need and the selection height to a size larger than the image.

I then click just above the edge of the image canvas.

 

2. If I need to make an exact size selection to include a corner of the image, I draw a Fixed Size selection on a new layer, keeping away from the canvas edges. 

I fill the selection with black, deselect, use Object Align to place it in the canvas corner I need to copy. Select whole layer, copy to clipboard, delete layer (or turn visibility off).

Back on the original image layer, use Alpha Mask.

 

 

The workarounds need a few more clicks but I use them all the time and I learned not to complain about trivial inconveniences.

[Rick Brewster]

btw, Fixed Size got a fix in the latest update that I forgot to put in the release notes. You can now use it with a simple click instead of having to click and drag for a few pixels. Not sure why I never noticed this before. It's much more precise this way.

[nadav]

I believe that fixed ratio is slightly harder to do per Djisves detailed instructions.

The whole point of fixed ratio is to have the selection be in the (wait for it) specified ratio 

PDN is a great tool that I use daily - I was so excited when the upgrade came out last week - but with respect, the fact that its "always been this way" does not mean that it's the best behavior.

Maybe there is a use-case I am missing, but what is the advantage of starting the selection outside the image boundaries?

[Djisves]

nadnav,

I agree. The workaround I describe above works fine for Fixed Size but it does not help when selecting Fixed Ratio.

My "it's always been this way" comment was just an observation and not meant as justification for the way PDN works. 

 

Rick,

Thank you for the fix and all your hard work.

[Rick Brewster]

Fixed ratio does what it's told but all selections are clamped to integer boundaries. So if you chose 16 : 9 ratio, you cannot draw a 17 pixel wide selection and be surprised when when it's 10 pixels tall instead of 9.5625 pixels tall. The alternative would be to only let the selection be at multiples of 16 pixels: 16x9, 32x18, etc.

[nadav]

Rick,

Thanks for (creating such a great tool and for) replying and looking into this.

Integer boundaries is understood, and is not the issue I am trying to raise.

 

What I meant, is that with fixed-ratio it is quite common to start the selection (mouse drag-point) outside the image boundaries, but to still expect that the actual selected pixels will conform to the fixed-ratio.

PDN currently calculates the ratio from the mouse drag-point, instead of from the image start-point.

This leads to the actual selection not being in the correct ratio.

 

In the screenshot below you can see that PDN describes the selection as 400x400, where in fact the actual pixels selected in the image are not 400x400, and do not conform to the 4:4 ration (no, I don't know why I did 4:4 ratio instead of 1:1  you can make fun of me later).

[Djisves]

... you can make fun of me later ...

Is it "later" already? 

Edited January 22, 2016 by Djisves

[Rick Brewster]

In the screenshot below you can see that PDN describes the selection as 400x400

No ... that's actually the image size. The selection size is listed as 257 x 388.