Precise relative positioning of layers

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GwentLarry
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Precise relative positioning of layers

Post by GwentLarry » Sat Apr 06, 2019 2:08 pm

I'm trying to merge 3 maps into a single map - each map is the order of 50 megapixel, although quite small files (2 -3 MB).

The maps are from the same source and should go together nicely, like a jigsaw :-)

I've removed detail from around the edges I don't want and converted to a transparent background. I'm putting the maps in different layers and then using Layer -> Transform .... to adjust one layer relative to the other. Then I'll merge them down into a single layer.

In principle, I think this should work - unless there's a better way?

I can't, however, shift, scale and rotate one layer with respect to the background layer with sufficient precision - the sliders are too coarse.

I would like to be able to adjust rotations by perhaps 0.1º, shift by almost pixel precision and scale to perhaps 0.1%, maybe even moreprecisely ...

Thanks,

regards,

Larry Stoter

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Re: Precise relative positioning of layers

Post by forum_adm » Sat Apr 06, 2019 5:46 pm

Larry,

the batch concat method is normally much quicker for this.

Thorsten

GwentLarry
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Re: Precise relative positioning of layers

Post by GwentLarry » Sun Apr 07, 2019 12:55 pm

Sorry, didn't explain myself very well.

These 3 maps, once I have removed, cleaned up and/or made transparent the areas I don't want to keep, are exactly like pieces of a jigsaw.

I don't want to simply place them next to each other - I want to slot them into each other so they need to overlap with adjustments in scale and rotation to get the edges to meet exactly.

I don't think concatenation does this? Doesn't concatentation simply place them edge-to-edge?

Thanks,

Larry

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Re: Precise relative positioning of layers

Post by forum_adm » Sun Apr 07, 2019 2:07 pm

Hi Larry,

yes, concat place them edge-to-edge.

Layers are the better choice if the images are arranged another way.

Thorsten

GwentLarry
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Re: Precise relative positioning of layers

Post by GwentLarry » Sun Apr 07, 2019 3:23 pm

OK, which was my understanding.

This returns to my orginal question - because the images are large (50 to 80 megapixel, I need to rotate very precisely. 0.5º over several 1,000 pixels is significant. The sliders controls in Layers -> Transform ... are not sufficiently precise.

Thanks,

Larry

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