Contour map gray resolution

[santhony94107]

For the last 16 years I've been re-writing for Windows a vector drawing program that I originally wrote for the Amiga (called ArtExpression). One of the features is a "blend" function that blends shapes, fill colors, line colors, etc. Using this blend function I have been creating contour maps for carving archtop guitar tops and backs (actually only half at one time because of the limited width of the machine).

My question is, is the depth of the cut based on values between 0 (Black) and 255 (white), or based on the RGB value of the color. If the latter, this could result in 768 sort-of gray levels rather than just 256. Like (128, 128, 12 would be a medium gray and (129, 128, 12 would be slightly "redder" and lighter, (129, 129, 12 again lighter, etc.

I'm trying to eliminate or reduce the "stair stepping" in the illustrations below:



This carving was based on this bmp file imported into designer:

[benluz]

For the last 16 years I've been re-writing for Windows a vector drawing program that I originally wrote for the Amiga (called ArtExpression). One of the features is a "blend" function that blends shapes, fill colors, line colors, etc. Using this blend function I have been creating contour maps for carving archtop guitar tops and backs (actually only half at one time because of the limited width of the machine).

My question is, is the depth of the cut based on values between 0 (Black) and 255 (white), or based on the RGB value of the color. If the latter, this could result in 768 sort-of gray levels rather than just 256. Like (128, 128, 12 would be a medium gray and (129, 128, 12 would be slightly "redder" and lighter, (129, 129, 12 again lighter, etc.

I'm trying to eliminate or reduce the "stair stepping" in the illustrations below:



This carving was based on this bmp file imported into designer:

do you have a scanner it has the ptn editor and you can see the gradient in the editor and it does not have the lines that you can see in your bmp file.The gradient is a smooth transition and carves the same way,yours is just reproducing the stepped effect that is visible in the bmp.
Ben

[santhony94107]

I did not quite understand what you were saying about the scanner???

What I was asking was if the depth of the cut is limited to 256 steps, or if I alter the software I have written to produce 768 steps, would the carving be smoother?

[benluz]

In the Scanner editor, we can see the grayscale gradient as you are showing in your BMP image,and you were asking about the stepping effect.I was just saying when viewing.... say a vectorart ptn the gradient has a very smooth transition where in your bmp you can see the stepping effect in the file ,so of course it would carve with a stepped effect.I would think the 768 step would be smoother.I guess what I'm trying to say ,is if the eye can see the stepping as I see in the bmp then the machine will pick it up as well.When we carve a curved surface that is designed by vector art or from designer, the curve is smooth ,I'm not sure what software they use to create their patterns ,but they are very crisp and clean and the grayscale gradients have no visible step lines.i hope this helps.
Ben

[santhony94107]

Thanks Ben. I'll try creating a 768 step bitmap and see if that smooths things out some. I don't have the probe scanner or the editor, so I can't really see what you mean.

[benluz]

Here is a section of a rifle stock scan in png format you can open it with most graphics program or use paint.net which is a free download, just do a search on google.In this scan you can get an idea of the gradient you need to get a smooth surface.
Ben


the center of this scan is maybe 3/4" deep where the rifle barrel sets into the forearm portion of the stock.This should give you an idea of what you need.Let me know how it works out
good luck !

[benluz]

I just caught the Amiga part of your post ...that was commodores hi-end machine back in the day ...I think ? I still have my commodore 64 and my pong game...lol Now I'm showing my age !
Ben

[liquidguitars]

For the last 16 years I've been re-writing for Windows a vector drawing program that I originally wrote for the Amiga (called ArtExpression).

Denise and Paula are in my thoughts....

LG

[pastime106]

In photoshop PS2 there is a tool called "blur tool" I copied your file to my hard drive and then played with it for a little while. I was able to to remove some of the stepping (on the screen view anyway) Might help, might not. To be honest the stepping that was left over in the original looks a lot easier to get rid of then the old caliper and pray method I have used in the past.

Regards,
Tom

[Jon Jantz]

Was gonna suggest the Gaussion blur as well. I use that to effectively remove a lot of the steps that occur with some of my Coreldraw creations also...