Black & White by means of unit of measure

[StrongBeaver]

How do you paint in Photoshop whereas 5000/1 micrometer/millimeter represents a value of black where for example; 5000 micrometer or 1 millimeter would be a

specific value of black, most likely 32-bit value and anything less then 5000/1 would be lower shade of black or gray ?

[NB, colourmanagement]

Hi

you're going to have to explain that question more s fully I fear.

maybe tell what you are trying to do?

thanks

neil barstow, colourmanagement

[StrongBeaver]

I want to paint black and white values equal to the micrometer or millimeter values.  For example, 5000 micrometer would be complete black in Photoshop, I hope that helps to understand ?

[davescm]

Hi

I still don't understand where these "micrometer or millimeter values" are. Are they in an existing image? Perhaps if you upload an image or section of an image and describe what you want in relation to that image we may be able to help.

Dave

[StrongBeaver]

What I mean, if you have a range of grey scale values, each grey scale value in that range would represent a UM or Millimeter unit of measure.

[NB, colourmanagement]

Hi

I'll admit I've still little idea what you wish to achieve, but does it help you to know that Photoshop can produce 256 differing values in a in a greyscale range - anywhere between 0,0,0 (black) and 255,255,255 ( White) .

You can paint with these specific using the brush tool, its value is set via the color pallet where you simply enter values between those I gave above, then simply paint.

Calculating how to distribute your data between these possible values will need to be done outside Photoshop.

I hope this is of help

if so, please mark as "helpful" or even "correct answer', so that others with a similar question can see that.

neil barstow

colourmanagement

[davescm]

I understand that you want to paint in greyscale and that each grey value will represent a unit of distance, be it millimetres or micrometres. What I don't understand is where you want to pick those distance values from.

Dave

[StrongBeaver]

davescm​ I have a chart of a micrometers / millimeters which I want to get those values from.  I suppose I have to find a way to convert sRGB or linear values to micrometers / millimeters or vise versa.

[Kenneth Kawamoto]

You need to write a script. The math itself would be simple - allocate the shortest length to pure white and the longest length in pure black, and divide 255 levels in between. Then draw a shape using the colour for each length from the data. I'd use JS or PHP (just because I know those), not sure if you can do this in Photoshop scripting...

[PECourtejoie]

Hello, Strongbeaver...You always come up with challenging questions!

I guess it is up to you to define the max and min length you have in the chart, then assign values to them.

Maybe draw a gradient from black to white (or vice versa) then use the height to select the value, and perform a linear selection that you then stretch on the entire area.

[Norman Sanders · Accepted solution]

Here are gray values from 100 as indicated. Do you you want to attribute a mm value to each?

(If this is helpful I can send you the actual file rather than this sample. It has greater accuracy.)

[StrongBeaver]

Do you you want to attribute a mm value to each?

Yes, or micrometer. The value chart is helpful, is this in sRGB values ?

[Norman Sanders]

It is a grayscale file which would allow you to Convert to your chosen profile.

[StrongBeaver]

Is it a larger gray scale image file then what you posted, if so; if you want to PM the file or attach a link to download ?

[Norman Sanders]

It is a file almost 2,000 pixels in width. Send a personal message that includes your email address and I will get it to you via WeTransfer along with additional details.