Description
Divide markerPhysicalLength by markerImagePixels for unitsPerPixel, then multiply by measuredImagePixels for physicalLength.
Layout calculations relate dimensions, offsets, and normalized positions in a drawing or display. A numeric coordinate depends on its origin and scale, while a size allowance must use the same length unit as the object.
Divide markerPhysicalLength by markerImagePixels for unitsPerPixel, then multiply by measuredImagePixels for physicalLength.
When to use this tool
Use Art Photo Scale Marker Ratio when you need a stated layout component from supplied dimensions or a normalized position.
How to use the tool and how it works
- Enter markerPhysicalLength, markerImagePixels, measuredImagePixels. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read physicalLength, unitsPerPixel. Use the output convention below.
Divide markerPhysicalLength by markerImagePixels for unitsPerPixel, then multiply by measuredImagePixels for physicalLength.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| markerPhysicalLength | Marker Physical Length | Required. Finite number; strictly above 0. |
| markerImagePixels | Marker Image Pixels | Required. Finite number; strictly above 0. |
| measuredImagePixels | Measured Image Pixels | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| physicalLength | Physical Length | Required. Finite number. |
| unitsPerPixel | Units Per Pixel | Required. Finite number. |
{
"input": {
"markerPhysicalLength": 10,
"markerImagePixels": 200,
"measuredImagePixels": 350
},
"output": {
"physicalLength": 17.5,
"unitsPerPixel": 0.05
}
}Limitations and assumptions
- Assumes a valid marker and common planar scale; perspective, lens distortion, depth differences, and measurement uncertainty are not corrected.
- 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
Check the assembled layout at its final scale and include installation or production allowances separately.
References
Similar or alternative tools
- Drawing Reference Length Ratio
Divide nonnegative drawingLength by positive referenceLength for ratio.
- Mural Grid Cell Scale
Divide positive muralCellSize by positive referenceCellSize for scaleFactor and multiply nonnegative referenceLength by that ratio.