Correct way to create PNG for Transparency

[Koko_NYC]

I am having difficulty in placing a PNG in Autocad 2017 making the background of the image transparent. I am inporting the PNG thru XREF command. 

 

The background of the image shows solid white color, regardless of the original image showing as transparent PNG. Additionally, the "Background Tranparency" setting udner AutoCAD properties does not seem to make any change. 

 

I suspect the issue is the creation of the PNG file and its settings. I am not a Photoshop expert but could follow steps if provided. 

 

Background: I need to insert my signature on a drawing. The signature was scanned and converted to PNG and white background removed as to give the transparency. When inserted in ACAD, the background shows as white color again. 

 

Thanks in advance,

 

 

[Cad64]

If the background was removed in Photoshop, so only your signature is visible, and then you saved to PNG format, Transparency should work in Autocad. I'm not sure why it isn't working. Can you provide your PNG file for testing? I realize it's your signature, so maybe you don't want to put it out there, so maybe you could try creating a PNG of something else?

[Koko_NYC]

Cad64,

 

I struggled but I was able to make it work - unfortunately I do not know how or exactly what I did, but it had something to do with the PNG image mode. 

 

I wish I could dig into this further and fully understand to to properly make this work, but now that I have the signature placed on the drawings, I don't think it makes sense to try to understand this.

 

Thank you again for taking the time to respond.

 

 

[CyberAngel]

I routinely xref signatures into title blocks. The trouble here may be in the image. You can't just erase the white background, you have to convert it to the transparent "color" (which is actually a lack of any color). My graphics editor has a command specifically for converting a color to transparency.

[Cad64]

2 hours ago, Koko_NYC said:

I struggled but I was able to make it work - unfortunately I do not know how or exactly what I did, but it had something to do with the PNG image mode. 

 

Well, at least you got it working.

 

In Photoshop, I typically just delete the background and then save as PNG format. Nothing fancy.

 

You mentioned the "Image Mode" though, and since your signature was scanned, the image mode was probably bitmap or grayscale. I'm guessing you changed it to RGB Color and that probably fixed the problem.

[BIGAL]

Ok the simplest way works every time, I had the same problem with scanned images not being quite right.

 

So insert your signature and just trace over using plines and fit spline etc then save as a block its line work so perfect  100% transparent. the more segments the smoother took me a couple go's, given its around 5mm in size looks perfect.

 

Done this multiple times different managers etc.

Edited October 31, 2019 by BIGAL

[tombu]

For those without Photoshop needing a free online tool for this I recommend LunaPic. Upload the PNG, from the options centered above the image select Transparent then switch Mode to Transparent color and wait till background appears light gray & checkered. You may need to select the color by picking it on the image.  When it looks correct save it, but I wouldn't override the original image just in case give it a new name.

https://www6.lunapic.com/editor/

[SLW210]

GIMP and Inkscape are free, also.

 

The link for LunaPic is blocked at work as network storage device.

[tombu]

https://www.online-image-editor.com/ does the job free online as well.

The amount of sites blocked where I work is both boggling and random.  I cannot access http://www.lee-mac.com, http://www.jtbworld.com and plenty of other work related sites at work.  I often download files home for lunch and email them to myself at work.

[SLW210]

There are a bunch of FREE or very cheap APPs and programs for removing the backgrounds of images, either for the computer or online.

 

GIMP is easy enough for me, very similar to Photoshop.

 

https://www5.lunapic.com/editor/?action=transparent actually works for me for the Lunpic site.

 

Just as crazy and random here. Yes, unfortunately many CAD sites are listed as blog sites and blocked or Social Media (though I can use Facebook and LinkedIn, which is odd). I do get YouTube now, but that was unblocked due to all of the help and instructional videos for the Laser Engraver are all YouTube.

 

[TerryDotson]

There is also a (now free) CUIX Tools which should take a CUIx file, change and fix the icon transparency in a single step.