Center photographed object on plain-colored background in 30 seconds

[Alpha23]

Hi folks,

 

As you all know, there is no possibility to center an object really quickly. Well, I just found a way to do it in 30 seconds. Prerequisite: the object background must be plain-colored, at least toward the edges on at least two adjoining edges.

 

Say you have the following picture (addedd a border - the picture itself has a white background):

Note: All edges are white.

As you can see, the car isn't centered properly because of the shadows. Of course you could expand your canvas and eyeball it but that's not what we're here for.

Ok, here's what you do:

 

• make sure your backround color matches the background of the object (K, right click on color)
• select all (Ctrl+A)
• select the "Move selection" tool (2 x M)
• drag the right and bottom selection edge to the edge of your object (in this case disregarding the shadow as it's not part of the object)

 

 

• invert the selection (Ctrl+I)

 

 

• add new layer (Ctrl+Shift+N)
• select the Paint Bucket (F) and fill the selected area

 

 

• duplicate layer and open the "Expand Canvas" dialogue (Ctrl+Shift+V,R - just stay on Ctrl+Shift)
• anchor on bottom right, select appropriate value (120% in my case) and confirm (Enter)

 

 

• rotate layer by 180° (Alt, L, 1)

 

 

 

• select move tool (M) and align one corner of the reversed L-shape to the corner of the other L-shape (top left) - quickly zoom in to the edge (Ctrl+Mouse Wheel)

 

 

• Crop to selection and delete two layers (Ctrl+Shift+X,Del,Del - stay on Ctrl+Shift)

 

 

Et voilá, you now have a centered object. Once you get the hang of it with those shortcuts, it won't take you longer than 30 seconds!

Questions? Suggestions? Compliments? Post here!

Edited April 1, 2021 by Alpha23
adjusted title

[ardneh]

Good tutorial.

 

A nice technique for those who are just learning to use paint.net, as it requires no plugins.
 

[midora]

Interesting for beginners to get in touch with the possibilities of paint.net.

 

But you are not only centering, you also increasing the size of the canvas (to keep the shadows). So the topic title was a little bit misleading to me.

 

I would just measure the distance to the left and right edge (using the rectangle tool), subtract the two values and use 'Canvas Size' anchored to the right edge and adding the difference to the width. Same for bottom/top.

[Alpha23]

Thanks for commenting.

Of course your approach works as well but imagine having lots of pictures to adjust - you won't do that every time. This version gets rid of all the numbers, which is why I find it neat.

A little side note about your comment on the title. You're right but you can get from any picture to a version like above and add a border afterwards, for example with an easy batch program like IrfanView64, which I use reeeeally often because it has so much possibilities for batch processing.

I've changed the title to make it clearer what I meant. This is about photographs of objects after all.

Edited April 1, 2021 by Alpha23

[Alpha23]

Oh and by the way, there is a plugin for centering an object if you're in need of that: