Issues with image scaling when copy and pasting

[T3G]

Hi there,

 

I'm new to the forum, but not to Paint.net, I've been using the program for the better part of 8 years. Recently I've run into an issue with scaling, however, that I would appreciate some assistance with.

 

I've always been into fantasy worlds and stuff like that, and for the last while I have been working on a fictional city based in the modern day. Recently, I decided I wanted a neighborhood with a street layout that resembled a space shuttle orbiter when viewed from above, so I found a picture of the optimum angle and got to tracing. When I finished and tried to insert it into the map, though, some issues came up. I'll demonstrate the issue using the base image rather than what I made.

 

When trying to crop the original image, I get a figure of 109.05 centimetres square, which is reasonable and is within the confines of what I was working with.

 

 

When I copy it over to the actual map, which is on a canvas many, many times larger than the image of the orbiter itself, it seems to hugely expand, though.

 

 

Similarly, if I measured the wing span of the shuttle, I got a little less than 8 cm on the base image.

 

But the wing span is tripled when it's inserted into the map.

 

I thought I had a pretty good grasp on how scaling works in the program, but now I'm not so sure. I always thought that images pasted onto a canvas would remain the same size regardless of if the canvas is the same size as the image or 100x larger. Does anyone know what I could be doing wrong here, and if there is a way to copy over the image with the scale maintained?

 

Many thanks for any and all responses

 

Andrew

[Eli]

Hello T3G,

 

Do both images have the same resolution (pixels/inch or pixels/cm)?

[Rick Brewster]

Copy/paste won't preserve DPI. I tried to implement this at one point and it was a mess. The Windows clipboard is a broken system that doesn't accommodate this.

 

Your images aren't actually growing or shrinking. Think in terms of pixels, not inches or centimeters, and things will make much more sense. Everything happens in terms of pixels.

 

Some good reading on the subject: http://forums.getpaint.net/index.php?/topic/17049-dpi-and-you-understanding-resolution-for-print-and-web/

[Eli]

If both images have the same resolution you should not have problems.

 I drew the red line on the shuttle image before copying it to the clipboard then I pasted over the map, traced the green line to check and it was 3.26 inches as in the original.

[T3G]

Hi all,

 

thanks for your responses. Eli, you were right, the resolution was not the same, the map is about 37 pixels/cm, while the shuttle image was 118 pixels/cm. I already have an established scale system for the map so it seems like the simplest solution will be to redo the entire shuttle shape from scratch, as much of a pain as that will be. A shame, but fortunately it wasn't the largest neighborhood to begin with.

 

Thanks again

 

Andrew