Examples with BFrame boofcv.alg.sfm.d3.structure.VisOdomBundleAdjustment.BFrame used on opensource projects

Example 16 with BFrame

use of boofcv.alg.sfm.d3.structure.VisOdomBundleAdjustment.BFrame in project BoofCV by lessthanoptimal.

the class MaxGeoKeyFrameManager method keepCurrentFrame.

/**
 * Perform different checks that attempt to see if too much has changed. If too much has changed then the
 * current keyframe should be kept so that new features can be spawned and starvation avoided.
 *
 * @return true if it should keep the current frame
 */
protected boolean keepCurrentFrame(VisOdomBundleAdjustment<?> sba) {
    BFrame current = sba.frames.getTail();
    CameraInfo camera = cameras.get(current.camera.index);
    // Compute fraction of the image covered by tracks
    coverage.reset(camera.maxFeaturesPerFrame, camera.imageWidth, camera.imageHeight);
    for (int i = 0; i < activeTracks.size; i++) {
        Point2D_F64 p = activeTracks.get(i).pixel;
        coverage.markPixel((int) p.x, (int) p.y);
    }
    coverage.process();
    return coverage.getFraction() < minimumCoverage;
}

Example 17 with BFrame

use of boofcv.alg.sfm.d3.structure.VisOdomBundleAdjustment.BFrame in project BoofCV by lessthanoptimal.

the class MaxGeoKeyFrameManager method selectOldToDiscard.

/**
 * Selects an older frame to discard. If a frame has zero features in common with the current frame it
 * will be selected. After that it scores frames based on how many features it has in common with the other
 * frames, excluding the current frame.
 *
 * @param totalDiscard How many need to be discarded
 */
protected void selectOldToDiscard(VisOdomBundleAdjustment<?> sba, int totalDiscard) {
    if (totalDiscard <= 0 || sba.frames.size < 2)
        return;
    frameToIndex.clear();
    for (int i = 0; i < sba.frames.size; i++) {
        frameToIndex.put(sba.frames.get(i).id, i);
    }
    // Create a histogram showing how observations connect the frames
    final int N = sba.frames.size;
    histogram.reshape(N, N);
    histogram.zero();
    // Skip the last row since it's not needed
    for (int frameIdxA = 0; frameIdxA < N - 1; frameIdxA++) {
        BFrame frame = sba.frames.get(frameIdxA);
        for (int trackIdx = 0; trackIdx < frame.tracks.size; trackIdx++) {
            BTrack track = frame.tracks.get(trackIdx);
            for (int obsIdx = 0; obsIdx < track.observations.size; obsIdx++) {
                BObservation o = track.observations.get(obsIdx);
                int frameIdxB = frameToIndex.get(o.frame.id);
                if (frameIdxA == frameIdxB)
                    continue;
                histogram.increment(frameIdxA, frameIdxB);
            }
        }
    }
    if (verbose != null)
        histogram.print("%4d");
    // See which keyframe the current frame has the best connection with
    // Most of the time it will be the previous frame, but if that was experienced a lot of motion blur it might
    // not be...
    int bestFrame = histogram.maximumRowIdx(N - 1);
    if (verbose != null)
        verbose.println("Frame with best connection to current " + bestFrame);
    // mark it so that it's skipped
    histogram.set(bestFrame, bestFrame, Integer.MAX_VALUE);
    for (int i = 0; i < totalDiscard; i++) {
        // Select the frame with the worst connection to the bestFrame. The reason the bestFrame is used and not
        // the current frame is that the current frame could be blurred too and might get discarded
        int lowestCount = Integer.MAX_VALUE;
        int worstIdx = -1;
        // N-1 to avoid the current frame
        for (int frameIdx = 0; frameIdx < N - 1; frameIdx++) {
            int connection = histogram.get(frameIdx, bestFrame);
            if (connection == Integer.MAX_VALUE)
                continue;
            // influence over the current frame's state and have no direct influence over bestFrame's state
            if (connection == 0) {
                if (verbose != null)
                    verbose.println("No connection index " + frameIdx);
                lowestCount = 0;
                worstIdx = frameIdx;
                break;
            }
            if (connection < lowestCount) {
                lowestCount = connection;
                worstIdx = frameIdx;
            }
        }
        if (verbose != null)
            verbose.println("Worst index " + worstIdx + "  count " + lowestCount);
        discardKeyIndices.add(worstIdx);
        // Mark the worst keyframe so it won't be selected again
        histogram.set(worstIdx, bestFrame, Integer.MAX_VALUE);
    }
}