Method Distance

testutil/image_hash.go:81–99

Distance calculates the distance between two hashes Returns error if hash types don't match

(other *ImageHash)

// Distance calculates the distance between two hashes
// Returns error if hash types don't match
func (h *ImageHash) Distance(other *ImageHash) (float32, error) {
	if h.hashType != other.hashType {
		return 0, fmt.Errorf("cannot compare hash type %d with %d", h.hashType, other.hashType)
	}

	switch h.hashType {
	case HashTypeSHA256:
		if h.sha256Hash == other.sha256Hash {
			return 0, nil
		}
		return 1, nil

	case HashTypeDct:
		return h.dctHashDistance(other), nil

	default:
		return 0, fmt.Errorf("unsupported hash type: %d", h.hashType)
	}
}

// Dump writes the hash to a writer
// Format: [1 byte: type][variable: hash data]