What format should images be in?

[SharkDesign]

When importing an image to use a decal I can never get it to come in at the correct size.

I've also noticed that the image will come in at a different physical size depending on the DPI and wondered if this was the reason for the image not being correct.

Does anyone know how to fix this problem?

I'm setting the size of the image in Paint Shop Pro and importing into Inventor 2010.

[Daniela_Koloszko]

There is information about this in the help file. Please see attached image. 

As you place an image in a sketch, a bounding rectangle shows you the size of the image. You can resize the image but you cannot change its aspect ratio. Its overall size changes, but not its proportions.

[SharkDesign]

Thanks for you reply. I know how to insert images, what I need to know is how to get it to come in at the correct size.

If I have an image which is 100mm by 100mm and I bring it into Inventor, it will no longer measure 100mm square.

[-niels-]

I just tried with simple images from photoshop.

I set the size to 40 mm x 20 mm and tried different dpi (72 dpi was standard, also tried 300 dpi)

Both images came in the same size, so i'm not sure why it isn't working for you.

What format are you using for the image? (i used .png)

What are the size and dpi settings you used in PSP?

edit: i attached my 300 dpi test image... what size does that come in for you?

[sam_m]

dpi with images is frankly a load of rubbish and just confuses the issue.

An image is a collection of pixels, the more pixels the more information and better the image at the expense of file-size.  Any image can be scaled to print at any size - thus dpi is practically useless.  Afaik it's only really used by graphic designers to ensure the images are kept small enough so there's enough pixel-information for the printer - eg if it's known the printer has a resolution of 600 dpi then a 600x600 pixel image scaled to 1" x 1" is the smallest you can realistically use as each pixel represents a blob of ink.  I've read that it can help if the image and printer resolution are multiples, so for a 1" print on a 300dpi printer you should be looking for an image resolution of 300, 600, 900 etc. - but tbh, it's not really needed.

When you bring an image into Inventor (import image command when in a 2d sketch) it has a boundary box and needs to be constrained in exactly the same way as everything else - so if you want the image to be 100mm tall then just dimension it as 100mm - the image will scale to suit.  So, no need to worry about dpi - in reality you just want to use as large an image as possible (within reason).  The max Inventor can import is 4096x4096, I think.

If you want a mask then have that colour in the bottom-right (? i think) pixel and choose the mask option in the image's Inventor property-box.

As for file-type...  personally avoid jpg's as they're evil and lossy (the compression ratio used corrupts the image data, so can become blocky) - so stick with png's (lossless compression, but can't remember Inventor being able to import them) or bmps (try to reduce colour-pallet with bmps or the file-size will be massive as it's an uncompressed format - personally strip them down to 4bit, 16 colours, for decals/silkscreens/labels in Inventor as I'm never going to print more than 16 colours.).

[-niels-]

Just had an interesting read on DPI here: http://www.rideau-info.com/photos/mythdpi.html

Thanks for raising my curiosity on that Sam_m

The OP want to bring in his images without having to dimension them, so he'll have to look at what his software is actually doing.

In my case Photoshop CS5 and IV2011 are doing what he wants, but he has different software...

As for .PNG: IV2011 let's you insert those, no problem.

[Anonymous]

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@-niels- wrote:

The OP want to bring in his images without having to dimension them, so he'll have to look at what his software is actually doing.

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It would still be best to dimension it, to make sure that everything is constrained.

Mike

[Anonymous]

You have to place the image in a sketch anyway, so just create some sketch geometry and constrain the image to that. Then the image will scale to the correct size.

I've attached an image of a relay where I downloaded the part file from the Omron website. I photographed each side of an actual relay, cleaned the images up using MS Office Picture Manager, then created a sketch on each face with the projected edges as construction lines. I inserted the image, constrained it to the projected geometry and created the decal.

Short of reverse-engineering and building a relay form the inside out (huge waste of time!) this is the easiest way to get a part to look like the real thing.

Hope this helps!

Scott

[SharkDesign]

THanks for everyones help, I still can't get it to come in at the correct size, but I can dimension it afterwards. I

 didn't actually realise you could dimension an image to start with.

The other problem I was having was that I was exporting the image from autocad and it was exporting at a really awful resolution, and once again, not the correct size. I found this link useful for producing a high res image from Acad.

http://www.cadforum.cz/cadforum_en/qaID.asp?tip=1028

[sam_m]

as said before....  there is no "correct size" for an image - don't bother worrying or even trying to work it out.  Ignore and forget any dpi settings/info for images.

like sketches and everything in Inventor, you need to dimension/constrain images placed in sketches - just constrain an edge of the image to a parallel face, dimension 1 edge to scale the image and then dimension to a point to place it.  By correctly constraining the image in the sketch you can always update/change the image outside of Inventor and as long as the aspect-ratio hasn't changed it will update and re-map within Inventor (if the aspect-ratio changes it will keep the size of the dimensioned edge and grow/shrink along the opposite axis).

Getting crisp and decent images form AutoCAD is a nightmare to itself.  I use "wmfout" command to create a wmf from AutoCAD - wmf are vector images so scale easily without becoming "blocky".  I then bring this wmf into CorelDraw to clean-up, adjust line-weights to make it look nice and colour, etc.  Then use CorelDraw's export command to create a bmp/png to bring into Inventor.  Yes, I know it sounds like a load of extra work, but found you HAVE to do something to AutoCAD's export to clean it up and make it look nice.

if you're new to images in Inventor, do not forget you have to decal them onto the part - don't just leave them floating in the sketch.  The decal command is helpfully hidden in the part's "create" drop-down from the ribbon.  This command is needed to wrap the image onto the suface below it - how you apply images to non-flat surfaces, etc.  (but, note there's a bug in Iv2011 that decals become corrupted if the part's surface has a bump-map - but think we're getting ahead of ourselves there).

finally - again, forget about image dpi...

[Daniela_Koloszko]

If there is a large difference before and after importing an image, this should be an issue. And we need to double check it.

So I wonder whether we can get a sample image you use.

If so, we can try to reproduce the issue and give out more detail explanation and solution.

[SharkDesign]

Thanks Daniela, please could you provide an email address that I can send the image to.

Everyone is saying to ignore the size and dimension it. However, AutoCAD knows exactly what size it is when you create the image and photoshop knows exactly what size the image is when I open it there. I could open the jpeg in any photo editing tool I like and it will be the same size. The same applies to desktop publishing and programs like Illustrator.

So how come when you bring it into Inventor the program has no idea what the size of the image is?

Am I missing something here?

[Daniela_Koloszko]

You can post the image here on this discussion topic, and I will download it from this item.

[SharkDesign]

I would rather not upload pictures of unreleased products on the internet.

I hope you understand.

[-niels-]

James, out of curiosity... did the test image i posted also come in at a wrong size for you?

[SharkDesign]

The 40x20 image comes in at 124.88x62.44mm

[-niels-]

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@SharkDesign wrote:

The 40x20 image comes in at 124.88x62.44mm

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Ok, since that image comes in correctly for me, i'd suggest Daniela uses my test image to see if she can get the same result you're getting.

[Daniela_Koloszko]

In my case the test image comes correctly in Inventor, image attached. I got the original image, so we will look at it and check what's wrong.