Help Importing a JPEG of known real dimensions

[Anonymous]

Hi,

Im looking for help on how to import a jpeg image of known size,  by this I mean the DPI resolution has been set in the EXIF header, so that the intended physical size of the actual jpeg image in known.

I understand this when outputting the image, so that the printer knows how big to make the final print.

But I want to import this JPEG into AutoCad so that it appears as the correct physical size.

The attachment file has the EXIF resolution set so the physical size should be 90 x 120 inches.  Ive tested this file in other CAD and its read ok

thanks

Leon

[maxim_k]

Hi Leon,

When you print this image, you print it with some resolution and physical dimensions depends on this resolution.
When you insert it to AutoCAD you can scale it to knowing dimensions with SCALE command after attaching to the drawing.

Maxim

[pendean]

Draw a 90x120 rectangle in AutoCAD and attached the image without scaling: do they fit? Try it, you'll answer all of your own questions then. Post back if you get stuck somewhere.

[Anonymous]

As the JPG image already has the dimension in it, i'd like the size to be automatic.

A bit more info, is that im doing some experiments with a photogrammetric camera called Spike that goes on your phone, and it produces a precisely scaled image.

So the idea is, take a photo of the side of a house, then import into AutoCAD, and all the dimensions are correct - so you can measure off the image.

hence the need for a automatic, direct import method.

any ideas?

Thanks

Leon

[maxim_k]

Do you have an idea to replace Spike application with AutoCAD?
Why? If you purchased Spike (with hardware measurement device) you can make measurements in Spike app. If you don't have Spike hardware, than AutoCAD will not able to act as Spike application.

Maxim

[pendean]

Thanks for revealing your intent. AutoCAD is the wrong software for the task.

I wonder if you read about Autodesk and point-clouds, for AutoCAD for Windows, and are assuming all reality-capture tools are the same. Read this about how point clouds are created and used in AutoCAD, it's helpful and you can decide if your camera can create point-clouds as required by AutoCAD https://www.augi.com/articles/detail/working-with-point-clouds

[Anonymous]

Hi - Thats pretty interesting that you know about Spike.  Do you have one?

So a little more info.. perhaps I should have said more to begin with.   Im the CTO of ikeGPS, and the inventor of Spike, and am looking at better ways of linking Spikes measurements to other applications.

We are prototyping a special Jpeg output from the Spike.

The Jpeg will be deskewed, eg the measurement surface, which is usually oblique to the camera, will be flattened.

Then we compute a resolution in DPI for the measurement surface, and apply this to the JPEG EXIF resolution fields.

The idea, is that a CAD package imports the JPEG, reads the resolutions and presents the image with the correct physical measurements.

This is intended to be a standard output, so for example, users can photograph the side of a building, put it into the CAD, and measure directly.

Ive tested the concept in CorelDraw, which our Signage customer base use,  and it works really well, it reads JPEG resolutions, get the image to the right size and makes downstream design work a lot simpler.

Now looking at how other systems react to this input.

Perhaps I should be building a DXF or DWG with an OLE embedded image.  Then I could have other layers with the measurements from the Spike system in it?

But thought the scaled JPG might be simple.

thanks,

Leon

leon@ikegps.com

[pendean]

>>>...Im the CTO of ikeGPS, and the inventor of Spike, ...<<<
Looks like you are ready to join the Autodesk Developer Network to port your product to AutoCAD: http://usa.autodesk.com/adsk/servlet/index?id=472012&siteID=123112

[Anonymous]

Hi - yes looking at that! and making enquiries about the RealDWG SDK.

thanks,

Leon

[Emmsleys]

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