Import image resolution.

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Import image resolution.

eslavko
Hello...
I have problem importing image (bmp or png). I can import image but scale is wrong. So how to set the resolution? Is there a option to do that? I import 300DPI image but I got near 10 times bigger one that it is.
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Re: Import image resolution.

dxli
LC does not manipulate DPI directly:

If you want to modify the relative size of the imported image: try the main menu: Modify -> Scale

There's drawing scale and printing scale, and it helps to do printer preview
eslavko wrote
Hello...
I have problem importing image (bmp or png). I can import image but scale is wrong. So how to set the resolution? Is there a option to do that? I import 300DPI image but I got near 10 times bigger one that it is.
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Re: Import image resolution.

eslavko
It's hard to measure that correctly. But at what DPI the image is imported? (I can generate proper image size before import)

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Re: Import image resolution.

dellus
It is imported with one unit per pixel. So for instance an image of 900x600 pixels will be in a drawing with meter set as unit ( edit - current drawing -units ) 900x600 meters. If you know with what dpi the image was scanned you can calculate the scaling factor you have to apply after importing. Or if you know an the real live size of something in the image, you can measure that in the drawing ( info - distance point to point ) and then calculate the necessary scaling factor to get it to the right size.  
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Re: Import image resolution.

eslavko
Thanks...
I try near all other possibility to change from DPI to correct scale. But now seems so easy. If image is 300DPI just need to resize to 0.08466% and get correct size.

Thanks...

Slavko.
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Re: Import image resolution.

SwervingLemon
This post was updated on .
You'd hope by now that it would be possible to get a plugin where you could just state that you're importing a 600dpi jpg and it would scale it properly on import. I see this thread is ancient but that's part of the problem. The instructions are now outdated, or were never clear to begin with.

The "scale" option has nearly opaque usability. It asks me for a reference point. That's cool. Scaling it down to 1/600th when my base units for the document are already established as inches does NOT result in a properly scaled image, and that's when I can figure out what the command reference in the corner is trying to tell me to do.

This is a common frustration I have with a lot of CAD software. The easiest way I have to import weird geometry pieces is to literally go place it on our massive flatbed scanner and scan it at 600dpi (it's max res in grayscale) and I can see in programs like Photoshop that it's a perfect geometrical representation.

Then I import it into CAD program of choice and I never get the option to say "It's 600dpi, just scale it proportionately and drop it at my cursor", no. I have to go through weird rituals every time because none of the software can check the EXIF or JPG properties. If we're going to have to go through the ritual ANYWAY, can't it just default to using the units already defined in the file information? Or at least provide some sort of import dialogue where you can say "no, the scale ISN'T arbitrary, those dpi actually mean something."?

Edit: Ok, apparently, my expressed preference for image insertion behaviour is apparently the default in DraftSight and AutoCAD. Why do LibreCAD, FreeCAD and others have to "go their own way" in this regard? It's pointlessly complex and frustrating.
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Re: Import image resolution.

dellus
AutoCAD and Draftsight are commercial software, with paid developers who can be told to do this or that. In LibreCAD many things could be done for improvement, but they are not done. By someone. There is no one.
Besides, not every image is coming from a scanner and does have a dpi value.
And not every drawing is in inches, and so on.

To keep things simple (softwarewise), some brainwork is left to the user. This has the positive side effect it's easier to achieve what you want sometimes. It can be a pain to get an automatic to do what you want.

OK, in the user interface it should be more obvious what to do. Or at least a better documentation, with examples.