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View Full Version : How do I fix this? Gray scale problem



Al Stewart
12-03-2010, 10:19 PM
I start with a color bit map image which includes a color gradient;
http://www.photocutouts.com/NON-website%20pics/0015.jpg

Converted to 8 bit gray scale looks like this;
http://www.photocutouts.com/NON-website%20pics/0014.jpg

Engraves like this; (showing top right corner of image)
http://www.photocutouts.com/NON-website%20pics/sample1.jpg

How do I avoid the stair-step gradient and how do I adjust it so there is more engraving in the lightest (marked with hash marks in photo) part of the gradient? It is almost not engraved at all. The black engraving is plenty deep enough already.

I see I also have to invert the gradient so the light color engraves deeper, but I think I will still have the stair-step problem, just on the other end. I ended up manually inverting the black and white in Photoshop because the white was not 100% white and the black wasn't 100% black. Forgot to invert the gradient.

Thanks!
Al

Photoshop CS4
CorelDraw X3
ULS Versalaser 40W
Vista

Chuck Stone
12-03-2010, 10:46 PM
Just curious .. have you tried leaving it as a color bitmap but using
Desaturate in Photoshop?

And rather than inverting the gradient, can you select the border that is
there and replace it with your own gradient? You don't want any 100%
white in it, since that won't engrave at all. (or it shouldn't..) If you set
the gradient points yourself, go from black to light gray if you want it to
engrave.. but the less black you have, the less engraving you get.

Al Stewart
12-03-2010, 11:17 PM
"...leaving it as a color bitmap but using
Desaturate in Photoshop?"

I have not, but I'm about to try that. It sounds like it may just solve the problem. May not have to replace the gradient either. Thanks!

Doug Griffith
12-04-2010, 11:35 AM
Since the yellow gradient is a design element with regards to color print, I don't think it needs to be translated to a laser etched image. I would lose the gradient all together and give a solid fill.

Dan Ashlin
12-04-2010, 12:06 PM
You could also try converting it to a greyscale halftone pattern in photoshop.