Engraving a bitmap: vector but not raster?

[Jeff Saltzman]

OK, strange one here...

I imported a bitmap image (8-bit), set up some text, and moved everything to position. Looked great. This was to engrave on a glass; my first glass and first use of the rotary attachment. The rotary set up fine, focus... check.

Then I tried printing with vector off, color mapping off, set the raster speed and power, 300dpi, and ran it.... only the text came out.

I checked the bitmap and it seemed ok, but I tried importing a higher res source bitmap (300 dpi exactly, no scaling) thinking the first was too low res... but it still won't engrave raster.

Testing without the rotary attachment, I was getting the same result-- text engraving raster, but not the image. Then, just for kicks, I turned on vector... and it engraved the bitmap!

What's going on? I searched the forum and couldn't find anything. I've engraved 8-bit bitmaps before as raster and they worked fine. What am I missing?

Thanks in advance for any clues!

btw this is running from CorelDraw 10 (Windows 98), with an Epilog Summit 25W.

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Update 10/20/10: I got it engraving in raster mode, but only with a 1-bit bitmap image!

Not sure why I could previously engrave an 8-bit bitmap in raster mode, but I'm over the hump for now, engraving Mason jars.

Looks like a lot of folks read my first post, but no reply... was it that obvious?

[Richard Rumancik]

Not obvious at all . . . probably no responses because no one had any ideas . . .

What type of bitmap were you importing? (bmp, tif, jpg?) Is it 8-bit grayscale?

It seems like maybe the print driver has some kind of filter on it so that if you check "raster" it blocks out anything that it thinks is "not raster". Then for some reason it treated your 8-bit bitmap as "not raster" and discarded it. (Why, I don't know. Unexpected file format? Bad header?) When you check both raster and vector it probably skips the filter. Just my guess how it might be set up internally.

If you send it 8-bit grayscale then it will convert to 1-bit internally when it prints. Personally, I think you are far better off sending it a prepared 1-bit file because you will have much more control of the outcome. You can select which conversion you use (Stuki, Jarvis, error diffusion, etc), can fiddle with intensities and will have a better idea of the result.

[Larry Bratton]

Jeff:
Why don't you post the graphic in question and let us see what the make up is.

[Jeff Saltzman]

OK, so I'm not crazy! The picture is an 8-bit BMP, a format I'm not used to dealing with, but figured using a Windows format with no (real) compression would be a good bet.

It's a pig-- the first image Google offers, and most appropriate for my friend who tended an 80-pounder last weekend for 24 hours, gently smoking with apple wood :) Not credited where I found it, seemed fair for a one-off gift! The pig was *amazing* but I had hoped to give him a mason jar emblazoned with "Pit Master" for the occasion; I'll just send him one now that I have it sorted out.

Anyway, here's the picture-- I just filled in the cut off tail and took out the color, nothing fancy. Attaching [the 8-bit image that didn't engrave and] the 1-bit image that did.

Er, the 8-bit bmp is too big to attach, so I uploaded it with sharing permissions to Google docs:
https://docs.google.com/leaf?id=0B8CUiP6WbJIvNjI2YzM5MjEtNWY2YS00ZmRkLWEwZ mUtZDBkZTk1M2RlZWQ0&hl=en&authkey=CMXEmIcP

[Terry Swift]

Jeff,

Good idea on the mason jars. People always like something different and if you sold them for a couple of bucks - you're probably still making something - not to mention having a customer on the hook for more "different" stuff.

In this day - we all have to "think outside the box."