Method compare

openbr/core/core.cpp:374–538

    }

    void compare(File targetGallery, File queryGallery, File output)
    {
        qDebug("Comparing %s and %s%s", qPrintable(targetGallery.flat()),
               qPrintable(queryGallery.flat()),
               output.isNull() ? "" : qPrintable(" to " + output.flat()));

        // Escape hatch for distances that need to operate directly on the gallery files
        if (distance && distance->compare(targetGallery, queryGallery, output))
            return;

        // Are we comparing the same gallery against itself?
        bool selfCompare = targetGallery == queryGallery;

        // Should we use multiple processes to do enrollment/comparison? If not, we just do multi-threading.
        bool multiProcess = Globals->file.getBool("multiProcess", false);

        // In comparing two galleries, we will keep the smaller one in memory, and load the larger one
        // incrementally. If the gallery set is larger than the probe set, we operate in transpose mode
        // i.e. we must transpose our output, to still write the output matrix in row-major order.
        bool transposeMode = false;

        // Is the larger gallery already enrolled? If not, we will enroll those images in-line with their
        // comparison against the smaller gallery (which will be enrolled, and stored in memory).
        bool needEnrollRows = false;

        if (output.exists() && output.get<bool>("cache", false)) return;
        if (queryGallery == ".") queryGallery = targetGallery;

        // To decide which gallery is larger, we need to read both, but at this point we just want the
        // metadata, and don't need the enrolled matrices.
        FileList targetMetadata;
        FileList queryMetadata;

        // Emptyread reads a gallery, and discards any matrices present, keeping only the metadata.
        targetMetadata = FileList::fromGallery(targetGallery, true);
        queryMetadata  = FileList::fromGallery(queryGallery, true);

        // Is the target or query set larger? We will use the larger as the rows of our comparison matrix (and transpose the output if necessary)
        transposeMode = targetMetadata.size() > queryMetadata.size();

        File rowGallery = queryGallery;
        File colGallery = targetGallery;
        qint64 rowSize;

        Gallery *temp;
        if (transposeMode) {
            rowGallery = targetGallery;
            colGallery = queryGallery;
            temp = Gallery::make(targetGallery);
        }
        else
            temp = Gallery::make(queryGallery);

        rowSize = temp->totalSize();
        delete temp;

        if (selfCompare)
            rowSize = queryMetadata.size();