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Normalize

Use the normalize transformation to stretch image luminance levels in a delivered image variant.

Overview​

Normalize can help low-contrast images use more of the available tonal range. It is useful for previews, generated assets, content images that look flat, and document images where stronger contrast can make text easier to read before OCR or review workflows.

Syntax​

FieldValue
Canonical parameternormalize
Aliasesnorm, normalise
Value syntaxBoolean, lower:upper, or an SDK object with lower and upper

Example​

https://cdn.imgwire.dev/{organization_id}/{environment_id}/{image_id}?normalize=true
image.url({
  normalize: true,
  format: 'auto',
  quality: 'auto',
});
imgwire images url img_123 --normalize true --format auto --quality auto

Before and after​

This example uses a low-contrast scan with faded text. Normalization stretches the tonal range so the document text is easier to read and more suitable for OCR preprocessing.

Low contrast scan with normalized contrast for more legible text
Low contrast scan with faded text before normalization

Best practices​

  • Use normalize on image classes that benefit from tonal correction.
  • Use normalize for low-contrast document captures when you need more readable text for OCR or human review.
  • Test on real uploaded content because normalization can affect images differently.
  • Use Contrast when you need a simpler contrast adjustment.

Common mistakes​

  • Normalizing images where accurate tones are required.
  • Applying normalize globally without checking edge cases.
  • Using normalize to compensate for poor source image capture.

Last updated at: May 9, 2026