Compare

The compare operation reports the difference between two images and generates an output image highlighting the differences between the two. For details of the values returned from this function, see compare operation output.

Properties

Reference image

Path to the reference image which is used as a basis for the comparison.

Comparison image

Path to the image to be compared against the reference image.

Comparison metric

The function used to quantify the difference between the two images:

  1. Mean absolute error
  2. Mean square error
  3. Peak absolute error
  4. Peak signal-to-noise ratio
  5. Root mean square error

Save annotated image

When checked, a new image will be created, highlighting the differences between the reference and comparison images.

Highlight style

The method used to highlight differences in the annotated image.

  1. Assign
    Assign the highlight colour to each differing pixel.
  2. Threshold
    Creates a black and white image, indicating the different areas.
  3. Tint
    Apply a tint to the different areas based on the highlight colour.
  4. XOR
    Mix the highlight colour and original colours using a bitwise XOR operation.

Highlight colour

The colour used to highlight differences in the annotated image.

Output file

Path to save the annotated image to.

Timeout

Timeout in seconds.

Output

Compare Operation Output

  • Difference Metric
    The result of the comparison metric for the entire image.
  • Absolute
    The absolute value of the comparison metric result.
  • Normalised
    The same result normalized against image size and colour depth.

GraphicsMagick.org