Grade Engrave... Oh Really?

[JamesW]

Hi All,

Over the last couple of years I've done loads of engraving and cutting... but something still eludes me - grade engrave.

If I import a bitmap (say, a PNG or a GIF) into Lasercut 5.3 then I can get it to engrave, just as long as it's 1-bit: just l
black and just white, no other colours.

If I import a greyscale bitmap into Lasercut, and try "Grade Engrave" then I get a problem.

The error message says "Engrave only support 2-bit bitmap!". (I like to read this in a comedy Chinese accent... but maybe that's just me.)

2-bit. That's four colours. Okay, so let's say I save a greyscale GIF with a 4-colour palette. Same problem. PNG? Same problem! Do the glorious software engineers of Lasercut 5.3 actually mean "2 colour" not "2-bit"? Is there something wrong with my procedure for creating 2-bit palettes? Will it only accept BMPs as input? Does Lasercut 5.3 only pretend to support Grade Engrave?

Thanks,

James

[Daven]

Hi James.
I know what you mean and grave engrave eludes me as I have not spent much time on it. It is possible though as I'm sure I have seen another users results.

If you save a jpg as pure 1 bit and import it to LC you get the same message on normal engraving - I'm not sure if the same happens with PNG.

I use IrfanView a lot and if you save a JPG in that with 1 bit selected the file won't engrave so I think LC needs 2 bit. Try opening the gray-scale image in MS paint save as a new file and try that - it is the quickest way I have fond to sort out any inconsistencies

Best
Dave

[TimBobTastic]

I have had limited success with Grade Engrave, but I only use vector graphics, not image files

My understanding is that is produces a ramp up to the feature (like a tree root). I have tried it with some rubber stamps and it does give support to fine detail (it effectively tapers from the bottom of the engraving to the usable face)

hope this is helpful?

[JamesW]

Hi All,

Okay, I think I've cracked it. My conclusions are:

* On these lasers Grade Engrave does NOT work with bitmap files. The "Engrave only work with 2-bit bitmap!" error message is simply bogus.
(I'd love to be proved wrong on this - but I have just used Imagemagick to create a series of 2-bit files in GIF, JPG, BMP, PNG and TIF formats, and I have used it to identify and set the exact composition of those palettes... and I've attempted to save them for Grade Engraving in Laserscript,.. unsuccessfully.)

* If you want to use Grade Engrave for things like rubber stamps, you can - but only with vector graphic input.

* If you want to engrave different depths for different shades of grey, you can! But not with Grade Engrave. How I've done it is this:

(1) Convert your image to N colours using your favourite Graphic Image Manipulation Programme. (I suggest N=4).

(2) Save off N-1 (i.e. 3 if N=4) 1-bit bitmaps (eg: GIFs) derived from thresholds, such that one of them shows black for the darkest colour, another black for the darkest and second darkest, and so on, until your final one bit bitmap is white, plus black covering every other colour area. (That final file, which has the most area of black coverage, is your "light grey" layer.)

(3) Import all your files into Laserscript, and try to keep track of which one's which. Set each one as a different cut group. Put all the images over each other in a stack.

(4) Work from light to dark. Engrave your biggest, "light grey" area first. Now engrave the next darkest layer. Keep going until you engrave your final, darkest layer (that'll have very little coverage). I'm not 100% positive that the order matters, but it seems logical.

Et voila! A beautiful, multi-layer engraving that takes absolutely ages to create. And probably even longer to adjust so that it looks better.

Hope his helps!

All the best,

James
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[Daven]

Well done James - will try it if I get time

Best
Dave