outputKeyframePly.m

function outputKeyframePly(PLYfilename, cameraRtC2W, data,fnameList)

fprintf('Writing ply point cloud file: ');

tic


frameInterval = 10;

pointCount = round(min(640*480*0.5,1000000/(length(data.image)/frameInterval)));


dataChunk = uint8([]);


for i=1:length(data.annotation.frames)
    if ~isempty(data.annotation.frames{i})
        
        frameID = find(ismember(fnameList,data.annotation.fileList{i}(1:end-4)));
        
        fprintf('%d ',frameID);

        image = imread(data.image{frameID});
        XYZcam = depth2XYZcamera(data.K, depthRead(data.depth{frameID}));        
        
        XYZcam = reshape(XYZcam,640*480,4)';
        isValid = find(XYZcam(4,:));
        XYZcam = transformRT(XYZcam(1:3,:),cameraRtC2W(:,:,frameID));
        try
            selID = randsample(length(isValid),pointCount);
        catch
            selID = randsample(length(isValid),pointCount,true);
        end
        isValid = isValid(selID);
     
        RGB =  reshape(image, 640*480, 3)';
        
        
        dataChunk = [dataChunk [reshape(typecast(reshape(single(XYZcam(:,isValid)),1,[]),'uint8'),3*4,[]); RGB(:,isValid)]];
    end
end




file = writePLYhead(PLYfilename, size(dataChunk,2));
fwrite(file, dataChunk,'uint8');
fclose(file);

toc;