A method of using image-based tube top circle detection, the method comprising: receiving, from at least one camera, a series of images of a tray, the tray comprising a plurality of tube slots, each tube slot configured to receive a sample tube, the series of images of the tray being acquired via the at least one camera; extracting, using a processor, for a given sample tube a plurality of candidates in each image of the series of images; computing, using the processor, a plurality of consistency scores, each of the plurality of consistency scores between candidates across images in the series of images from possible combinations of the plurality of candidates; accumulating, using the processor, the plurality of consistency scores; and selecting, using the processor, a true tube top circle for the given sample tube for each image in the series of images based on a highest consistency score between candidates across the images in the series of images, wherein computing the plurality of consistency scores comprises: determining, using the processor, the possible combinations of the plurality of candidates; computing, using the processor, properties for each of the possible combinations, the properties based on characteristics of respective ones of the plurality of candidates; and computing, using the processor, the plurality of consistency scores based on the computed properties, wherein the properties comprise one or more of circle diameter, circle center location, circle height, and circle center offset, or comprise one or more of shape and texture across image patches. receiving, from at least one camera, a series of images of a tray, the tray comprising a plurality of tube slots, each tube slot configured to receive a sample tube, the series of images of the tray being acquired via the at least one camera; extracting, using a processor, for a given sample tube a plurality of candidates in each image of the series of images; computing, using the processor, a plurality of consistency scores, each of the plurality of consistency scores between candidates across images in the series of images from possible combinations of the plurality of candidates; accumulating, using the processor, the plurality of consistency scores; and selecting, using the processor, a true tube top circle for the given sample tube for each image in the series of images based on a highest consistency score between candidates across the images in the series of images, wherein computing the plurality of consistency scores comprises: determining, using the processor, the possible combinations of the plurality of candidates; computing, using the processor, properties for each of the possible combinations, the properties based on characteristics of respective ones of the plurality of candidates; and computing, using the processor, the plurality of consistency scores based on the computed properties, wherein the properties comprise one or more of circle diameter, circle center location, circle height, and circle center offset, or comprise one or more of shape and texture across image patches. determining, using the processor, the possible combinations of the plurality of candidates; computing, using the processor, properties for each of the possible combinations, the properties based on characteristics of respective ones of the plurality of candidates; and computing, using the processor, the plurality of consistency scores based on the computed properties, wherein the properties comprise one or more of circle diameter, circle center location, circle height, and circle center offset, or comprise one or more of shape and texture across image patches.