How to crop image and/or canvas into a triangle?

Canon EF-S 18-200mm f/3.5-5.6 IS

04/26/2007 10:10:43 AM · #1

How does one do that ?

CEJ

Canon EOS-40D

04/26/2007 10:42:06 AM · #2

Funny you should ask this as last night I experimented with ways to do just this. I don't use PhotoShop, I use PhotoImpact so you may need to translate:

1. Bezier curve selection tool - I used this to define the triangle I wanted, created a new object from it, placed object on a new layer, then placed new layer onto existing canvas where I wanted to use it. Worked quite well and found it to be the easiest.

2. Perspective crop - this allows you to define an irregular area, but also distorts the image way to much as after you make the rectangle a triangle it thinks you want to correct so it significantly changes the perspective/shape of the objects in cropped area. Not very effective if the defined area has definitive shapes as opposed to just color/sky, etc.

3. Create new layer, using object eraser, erased all but triangular area I wanted to use. This layer was then placed on canvas I wanted to use. This also worked quite well, but only if soft edge was set to zero. Took a few tries as any movement of the eraser erases (obviously) so if you are not steady, the clean edge you want may not be so clean.

So, overall, I found the Bezier curve selection tool to be the easiest. I would be interested to know other's methods.

ETA: Hope this helps.

Message edited by author 2007-04-26 10:45:17.

Telehubbie

Canon EOS-40D

Canon EF 24-70mm f/2.8L USM

04/26/2007 11:04:34 AM · #3

I've never done it, but try this:

Use the Polygonal Lasso tool and draw your triangle, clicking at each corner then bring it back to the original spot. Make sure anti-aliasing is checked and feather is set to "0." I'm not sure if there's a way to draw each line the same length to create an equilateral triangle, but you could use the measurement tool (under the eye-dropper tool) to measure each line to see how close they are and try until you get it right. Then you could probably just crop the selection like normal.

Again, I'm not sure if that will work, and I'm probably missing something somewhere, I don't have PS here at work to try it out. Just going off the top of my head. Good luck!

GeneralE

Canon PowerShot S3 IS

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

04/26/2007 11:11:33 AM · #4

Something like this?

Sony 24-70mm F4 Vario-Tessar T* FE OSS

04/26/2007 11:27:11 AM · #5

Now you are talking, Paul ... now if we only do that to the canvas ...

Bear_Music

Samsung Galaxy S24 Ultra

04/26/2007 11:42:28 AM · #6

Originally posted by Greetmir:

Now you are talking, Paul ... now if we only do that to the canvas ...

If you're doing it for web viewing, photoshop supports transparent backgrounds. In other words, you can create a round or whatever shape image to paste in a web site and the BG of the web site will show through the transparent BG of the image rectangle.

R.

Nikon AF Nikkor 20mm f/2.8D

04/26/2007 03:26:08 PM · #7

OOooOOooOO ... NOW you got me thinking ... THANKS, Robert!

LanceW

Nikon Z9

04/26/2007 03:33:31 PM · #8

You mean like this?

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

04/26/2007 04:32:05 PM · #9

Originally posted by Bear_Music:

Originally posted by Greetmir:
Now you are talking, Paul ... now if we only do that to the canvas ...

If you're doing it for web viewing, photoshop supports transparent backgrounds. In other words, you can create a round or whatever shape image to paste in a web site and the BG of the web site will show through the transparent BG of the image rectangle.

R.

IF you save as GIF or PNG

dassilem

Nikon D90

04/26/2007 04:48:38 PM · #10

Originally posted by GeneralE:

Something like this?

Funny!

Nikon AF Nikkor 20mm f/2.8D

04/26/2007 04:50:52 PM · #11

Originally posted by tooohip:

You mean like this?

Yeah like that ... how did you do that ?

LanceW

Nikon Z9

04/26/2007 04:52:08 PM · #12

Originally posted by Greetmir:

Originally posted by tooohip:
You mean like this?

Yeah like that ... how did you do that ?

Well, as you can see from your quote, I saved as a jpg which means I needed to use the same background color as where it would be displayed. If you save as a gif or png, you can select transparent background and put it anywhere on the web to retain the triangle look.

Edit to add how I did the effect. Opened image in PS CS2, used the pen tool to create a triangle. Made the shape into a selection. Inversed the selection and hit delete.

Message edited by author 2007-04-26 16:53:14.

04/26/2007 04:52:30 PM · #13

Originally posted by Art Roflmao:

Originally posted by Bear_Music:

Originally posted by Greetmir:
Now you are talking, Paul ... now if we only do that to the canvas ...

If you're doing it for web viewing, photoshop supports transparent backgrounds. In other words, you can create a round or whatever shape image to paste in a web site and the BG of the web site will show through the transparent BG of the image rectangle.

R.

IF you save as GIF or PNG

Yeah but maybe I am dense ... I am missing what you are saying here ... I don't quite understand ...

04/26/2007 04:54:40 PM · #14

Originally posted by tooohip:

Originally posted by Greetmir:

Originally posted by tooohip:
You mean like this?

Yeah like that ... how did you do that ?

Well, as you can see from your quote, I saved as a jpg which means I needed to use the same background color as where it would be displayed. If you save as a gif or png, you can select transparent background and put it anywhere on the web to retain the triangle look.

Edit to add how I did the effect. Opened image in PS CS2, used the pen tool to create a triangle. Made the shape into a selection. Inversed the selection and hit delete.

OK ... no not like that ... I don't wanna see the rectangular frame ... but heck ... we have to enter shots as JPG right ???

... and how did you make a perfect equilateral triangle with the pen tool ?

Message edited by author 2007-04-26 16:59:09.

04/26/2007 04:57:14 PM · #15

I could have sworn that I saved .jpg cut and pasted portions onto a .jpg transparent background before ...

04/26/2007 05:00:25 PM · #16

jpg's won't do transparency. What tooohip did was as he said - matched the photo background color with the web page background.

Transparencies only work with GIF or PNG formats and I don't think DPC allows PNGs at all and GIFs only for portfolio - not challenges.

04/26/2007 05:04:54 PM · #17

Also - as far as creating an irregular (non-rectangular) frame or "crop" - I use the Custom Shapes tool. Make sure your photo is on an unlocked (not Background) layer, create a new layer on top of your image, put a custom shape on it, make your photo layer active, then CTRL+click on the shape layer in the layer pallette to create an instant selection the shape of the shape, ALT+I+P to crop the whole image to the extents of the mask, then CTRL+SHIFT+I to invert the mask, then hit delete to remove the unwanted portions of the photo. Then you can delete the shape layer if you want.

Message edited by author 2007-04-26 17:05:14.

04/26/2007 05:14:35 PM · #18

OK thanks ... but images submitted for challenges must be .jpg so no none rectangular crops can be submitted ... even if you use the same colour as the background DPC puts a one pixel black rectangular frame around it as it did on toohips image but you can't see it on one of the .gif thumbnails ... you can on the photo page ... sigh ... I thought I had something there for a minute or three ... LOL

04/26/2007 05:16:04 PM · #19

Yeah, I wish the black border would be removed. I think it has been suggested.

DjFenzl

04/26/2007 05:19:10 PM · #20

Originally posted by Greetmir:

it has been tried before...