Description
Calculate placed image pixels per inch independently along each axis.
Print and screen geometry depends on coordinate scale, placed image size, bleed/inset definitions and pixel transparency. Placed pixels per inch differs from printer dots per inch, and a caller-chosen margin differs from a verified production tolerance. Empty-image conventions and threshold equality affect bounding results.
Calculate placed image pixels per inch independently along each axis.
When to use this tool
Use Image Effective DPI Placement when checking the stated artwork geometry, placement, screen angle or alpha-bound convention.
How to use the tool and how it works
- Enter pixelWidth, pixelHeight, placedWidthInches, placedHeightInches. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read horizontalDpi, verticalDpi. Use the output convention below.
Require positive whole pixel dimensions and positive placed dimensions in inches. Return pixelWidth/placedWidthInches and pixelHeight/placedHeightInches separately.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| pixelWidth | Pixel Width | Required. Safe integer; minimum 1. |
| pixelHeight | Pixel Height | Required. Safe integer; minimum 1. |
| placedWidthInches | Placed Width Inches | Required. Finite number; strictly above 0. |
| placedHeightInches | Placed Height Inches | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| horizontalDpi | Horizontal placed pixels per inch, not physical printer dots per inch. | Required. Finite number. |
| verticalDpi | Vertical placed pixels per inch; may differ from horizontal if placement is distorted. | Required. Finite number. |
{
"input": {
"pixelWidth": 1200,
"pixelHeight": 800,
"placedWidthInches": 4,
"placedHeightInches": 2
},
"output": {
"horizontalDpi": 300,
"verticalDpi": 400
}
}Limitations and assumptions
- These are placed pixels per inch despite DPI output names; actual printer dots, resampling, image quality and suitable print resolution are not determined.
- 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 rendered artwork and verified production/device specifications for actual print quality, cropping, fit and manufacturing requirements.
References
Similar or alternative tools
- Bitmap Trim Transparent Border Count
Find transparent raster borders using a supplied alpha threshold.
- Image Resolution Enlargement Limit Gap Tool
Calculate image resolution enlargement limit gap from explicit caller-supplied inputs.