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SIFT Comparison

Version v1

Compare SIFT descriptors from multiple images using FLANN-based matcher.

This block is useful for determining if multiple images match based on their SIFT descriptors.

Type identifier

Use the following identifier in step "type" field: roboflow_core/sift_comparison@v1to add the block as as step in your workflow.

Properties

Name Type Description Refs
name str The unique name of this step.. ❌
good_matches_threshold int Threshold for the number of good matches to consider the images as matching. ✅
ratio_threshold float Ratio threshold for the ratio test, which is used to filter out poor matches by comparing the distance of the closest match to the distance of the second closest match. A lower ratio indicates stricter filtering.. ✅

The Refs column marks possibility to parametrise the property with dynamic values available in workflow runtime. See Bindings for more info.

Available Connections

Check what blocks you can connect to SIFT Comparison in version v1.

The available connections depend on its binding kinds. Check what binding kinds SIFT Comparison in version v1 has.

Bindings

  • input

    • descriptor_1 (numpy_array): Reference to SIFT descriptors from the first image to compare.
    • descriptor_2 (numpy_array): Reference to SIFT descriptors from the second image to compare.
    • good_matches_threshold (integer): Threshold for the number of good matches to consider the images as matching.
    • ratio_threshold (integer): Ratio threshold for the ratio test, which is used to filter out poor matches by comparing the distance of the closest match to the distance of the second closest match. A lower ratio indicates stricter filtering..

  • output

    • good_matches_count (integer): Integer value.
    • images_match (boolean): Boolean flag.
Example JSON definition of step SIFT Comparison in version v1 
{
    "name": "<your_step_name_here>",
    "type": "roboflow_core/sift_comparison@v1",
    "descriptor_1": "$steps.sift.descriptors",
    "descriptor_2": "$steps.sift.descriptors",
    "good_matches_threshold": 50,
    "ratio_threshold": 0.7
}