An computer-implemented image analysis method for analysing images by inputting said images into an image analysis module having a neural network trained for image analysis, said images being taken by an image taking method, said image taking method comprising: taking images with a microscope and selecting an image from the taken images for image analysis, in the image taking method taking the images of a sediment of a liquid filled in an analyzing space located between a transparent upper window portion and a transparent lower window portion of a container adapted for analyzing a liquid, wherein the sediment is centrifuged on an inner flat surface of the lower window portion, wherein the image taking method comprises: - taking, in a first spatial region of the analyzing space, a first depth image sequence at focal plane positions shifted with an equal step size in a depth direction perpendicular to the flat surface, and selecting from the first depth image sequence the image with the best contrast for image analysis, - taking, in a second spatial region of the analyzing space, a second depth image sequence at focal plane positions shifted with an equal step size in the depth direction, wherein the step size of the second depth image sequence is the same or is smaller than that of the first depth image sequence, wherein the second depth image sequence has fewer images than the first depth image sequence, and wherein one of the intermediate focal plane positions from the focal plane positions of the second depth image sequence is the same as the focal plane position with the best contrast of the first depth image sequence, and selecting from the second depth image sequence the image with the best contrast for image analysis, and - also selecting, for image analysis, at least one additional image from each depth image sequence, wherein the focal plane position of the at least one additional image is located at the same relative distance from the best-contrast focal plane position in each depth image sequence. - taking, in a first spatial region of the analyzing space, a first depth image sequence at focal plane positions shifted with an equal step size in a depth direction perpendicular to the flat surface, and selecting from the first depth image sequence the image with the best contrast for image analysis, - taking, in a second spatial region of the analyzing space, a second depth image sequence at focal plane positions shifted with an equal step size in the depth direction, wherein the step size of the second depth image sequence is the same or is smaller than that of the first depth image sequence, wherein the second depth image sequence has fewer images than the first depth image sequence, and wherein one of the intermediate focal plane positions from the focal plane positions of the second depth image sequence is the same as the focal plane position with the best contrast of the first depth image sequence, and selecting from the second depth image sequence the image with the best contrast for image analysis, and - also selecting, for image analysis, at least one additional image from each depth image sequence, wherein the focal plane position of the at least one additional image is located at the same relative distance from the best-contrast focal plane position in each depth image sequence.