Grey Scale

[James RS]

Does anybody happen to know how the greyscale equates to depth, such as 50% does that equal a 1/2" and so on.

Thanks,
Jim

[pine acres woodshop]

If you are carving 1" deep I would say it equals 1/2", I think it depends upon your depth of cut ,say on a 1/2" carve 50% would be 1/4". I could be wrong, this is my best guess.
Mark

[Amonaug]

All depends on the depth setting of the pattern and height setting. Al, Chris or Ken had a post on the forums somewhere with a formula, will have to look for it.

Basically if the depth of the pattern is 1/2"(0.50) and the height at 100 makes the pattern 1/4" (0.25) thick (thus making the top of the pattern 1/4" below the surface of the board) then a grey of 128,128,128 (50%) would make that point about 3/8" (.375) deep from the surface of the board.

EDIT: My mistake it was Jeff Birt

"While working on a new feature for CBPE I needed to figure out the mathematical relationship between Depth and Designer. I made up a test pattern of three 100x100 pixel squares; one black, one 50% grey and one white. I imported this pattern into Designer using the default settings. I did invert the pattern to bring back the correct white = 0, black = 255 relationship, which is how a pattern is set up internally so I still can't figure out why Designer inverts it on import. The pattern was placed on the board at its default depth of 0.25" and a number of measurements taken at various heights. The Depth was increased to 1" and the process repeated.

As you know a pattern is basically an 8-bit (0-255) grey scale image where the level of grey determines the height of a given point. If your pattern takes up the entire range of grey then you can use the following formula to accurately set both the depth (bottom of) and height (top of) a pattern when placing it on the board. If your pattern does not span the entire grey scale then this will not be accurate.

I'm working on a way to distribute a pattern over the entire grey scale and have the ability to set its default settings so that, when it place on the Board in Designer, you will have a known Depth and Height. I thought others might benefit from knowing the exact relationship between Depth and Height for placing patterns.


actualDepth = -0.0025 * Height * (greyLevel/255) +Depth

actualDepth = Depth from top of board at given point
greyLevel = level of grey of given point (0 to 255)
Height = Height setting in Designer
Depth = Depth setting in Designer
"

You can determine the depth of any point on the board in Designer by hovering your mouse over that point and looking in the lower left corner of the designer window you'll see something like

Front Face: 1.27" x 2.05" x .045"

The 3rd number is the depth of the point on the board.

[James RS]

Thank you!