Description
Calculate the signed offset from a supplied grayscale black-point reference.
Graphic-design metadata distinguishes font metrics, variable-font axes, fill rules, color labels and design-token units. Numeric axis differences and text labels do not render a font or apply a color profile. The source convention must match before comparing metrics or resolving a design-system reference.
Calculate the signed offset from a supplied grayscale black-point reference.
When to use this tool
Use Grayscale Profile Blackpoint Offset when checking the stated font, color or design-token convention.
How to use the tool and how it works
- Enter channelValue, suppliedBlackPoint. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read blackRelativeValue. Use the output convention below.
Return channelValue-suppliedBlackPoint as a signed channel-coordinate difference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| channelValue | Channel Value | Required. Finite number. |
| suppliedBlackPoint | Supplied Black Point | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| blackRelativeValue | Black Relative Value | Required. Finite number. |
{
"input": {
"channelValue": 0.5,
"suppliedBlackPoint": 0.1
},
"output": {
"blackRelativeValue": 0.4
}
}Limitations and assumptions
- No profile is loaded, unit range enforced or color-space/black-point conversion performed.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Inspect actual fonts, rendered paths, color profiles and the complete applicable design-system specification for visual or production decisions.
References
Similar or alternative tools
- Spot Color Tint Percent Label
Label a spot-color tint using a percentage from zero to one hundred.
- Font Axis Default Reference Offset Tool
Normalize one supplied font-axis value relative to an explicit default/scale, without loading a font.