Histology Annotation Physical Area Term Tool

Description

Multiply nonnegative pixelArea by positive xMicronsPerPixel and yMicronsPerPixel for squareMicrons, then divide by one million for squareMillimeters.

Histology images and sections have pixel scales, physical dimensions, cutting indexes, and processing changes. Geometric arithmetic depends on those conventions and does not identify tissue or establish diagnostic adequacy.

Multiply nonnegative pixelArea by positive xMicronsPerPixel and yMicronsPerPixel for squareMicrons, then divide by one million for squareMillimeters.

When to use this tool

Use Histology Annotation Physical Area Term when you need one explicit histology image-scale or section-geometry component.

How to use the tool and how it works

Enter pixelArea, xMicronsPerPixel, yMicronsPerPixel. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read squareMicrons, squareMillimeters. Use the output convention below.

Multiply nonnegative pixelArea by positive xMicronsPerPixel and yMicronsPerPixel for squareMicrons, then divide by one million for squareMillimeters.^[1]

Input field	Meaning and units	Accepted input
pixelArea	Nonnegative area measured in square pixel-coordinate units.	Required. Finite number; minimum 0.
xMicronsPerPixel	X Microns Per Pixel	Required. Finite number; strictly above 0.
yMicronsPerPixel	Y Microns Per Pixel	Required. Finite number; strictly above 0.

Output field	Interpretation	Returned shape
squareMicrons	Square Microns	Required. Finite number.
squareMillimeters	Square Millimeters	Required. Finite number.

json

{
  "input": {
    "pixelArea": 1000000,
    "xMicronsPerPixel": 0.5,
    "yMicronsPerPixel": 0.5
  },
  "output": {
    "squareMicrons": 250000,
    "squareMillimeters": 0.25
  }
}

Limitations and assumptions

PixelArea is an image-coordinate area rather than a length; scales must correspond to that image level and no segmentation or scanner calibration is 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

Verify calibration, section preparation, image registration, and the complete sampling protocol before interpreting tissue measurements.

References

Calculation and input contract: histology/histology-annotation-physical-area-term — tool.io

Similar or alternative tools

Region Area Pixel Scale
Subtract excludedPixels within nonnegative integer pixelCount and multiply by positive xLengthPerPixel times yLengthPerPixel.
Slide Scanner Microns Per Pixel Factor
Multiply positive baseMicronsPerPixel by positive downsample for levelMicronsPerPixel, then by nonnegative pixels for lengthMicrons.