Legacy ImageMagick Discussions Archive

I need to make several images 4 times bigger, and I need them to fit normally in a background, without anti-aliasing or anything similar - I need it's outside to be sharp. Now, I know -scale does exactly that, but -resize makes it look infinitely better. I can't however use -resize because it blurs the outside shape of the image too, making it not work the way I want with the background. My question is the following:
Is there a way to make an image be blurred on the inside, the same way it is when you -resize it, but still have perfectly sharp edges, the same way it is when you -scale it?

I'm quite sure I should be using masks to do this, but I really don't have any idea how to, so I'm asking you guys.

Examples:
Resized:

Scaled:

(I used -median 10 too on both so they look better)

The image should look smooth as the first one, but have sharp edges and fit on a background that doesn't support transparency just like the second.

Thanks in advance!

I'm not entirely clear what you are asking. Can you provide the image you want enlarged?

Maybe you want to:

1. Create an image of the red background, transparent where the hand and gun were. Scale this 400%.

2. Resize the original 400%.

3. Place image (1) over image (2).

The red background is just an example, I actually want to use it in a game that doesn't work with partial transparency, only boolean, so I need it to have indeed a transparent bg, but one that would look normal if I were to fill it with a random color or paste it over a background image. Yes, I assume what you said would work perfectly for what I want. The thing is - I need to do that in batch. Is there any scripted way to make something similar to that easily?

This is the picture I'm using as an example:

Ah, you want to enlarge the image, but ensure the transparency is binary rather than a transition?
You could use mogrify to do many images in one command.

Alright, look:

I need to find a way to make the initial small image into something like the one above I made manually. That one looks EXACTLY the way I need it to - somewhat blurred just like when -resized, but with sharp pixelated edges just like when -scaled.

Is there any kind of simple way to make something like that?


(Thanks for your help, snibgo, but using the exact threshold example you posted me gave this output)

On IM v6.7.9 and 6.8.1, on Windows 7, I get a different output to you. What version are you on?

I am still unclear what edge result you want. The edges in your "manual" version (which I can get close to with "-morphology dilate disk:8") don't look like what I get with "-scale".