---
name: "idiff"
section: "1"
platform: "linux"
package: "openimageio-tools"
version: "2.5.18.0+dfsg-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/idiff"
---

# idiff(1)

## NAME

**idiff -- compare two images**

## SYNOPSIS

```
Usage: idiff [options] <image1> <image2 | directory>
```

## DESCRIPTION

**This program is part of the OpenImageIO (http://www.openimageio.org) tool suite.** **Detailed documentation is available in pdf format with the OpenImageIO** **distribution.**

## OPTIONS

- **--help**

  **Print help message**

- **--version**

  **Print version and exit**

- **-v**

  **Verbose status messages**

- **-q**

  **Quiet (minimal messages)**

- **-a**

  **Compare all subimages/miplevels**

**Thresholding and comparison** *options*

- **-fail VAL**

  **Failure absolute difference threshold (default: 1e-06)**

- **-failrelative VAL**

  **Failure relative threshold (default: 0)**

- **-failpercent PERCENT**

  **Allow this percentage of failures (default: 0)**

- **-hardfail VAL**

  **Fail if any one pixel exceeds this error (default: inf)**

- **-allowfailures N**

  **OK for this number of pixels to fail by any amount (default: 0)**

- **-warn VAL**

  **Warning absolute difference threshold (default: 1e-06)**

- **-warnrelative VAL**

  **Warning relative threshold (default: 0)**

- **-warnpercent PERCENT**

  **Allow this percentage of warnings (default: 0)**

- **-hardwarn VAL**

  **Warn if any one pixel exceeds this error (default: inf)**

- **-p**

  **Perform perceptual (rather than numeric) comparison**

**Difference image** *options*

- **-o FILENAME**

  **Output difference image**

- **-od**

  **Output image only if nonzero difference**

- **-abs**

  **Output image of absolute value, not signed difference**

- **-scale FACTOR**

  **Scale the output image by this factor (default: 1)**