A method of autofocus

Abstract

The invention discloses an automatic focusing method, which includes moving the camera's focus motor downward for 80 steps to determine whether the traversal is completed. If the traversal is not completed, calculate the sharpness of the image, and determine the size of the sharpness and the set threshold. , if the definition is less than or equal to 1 / 2 of the set threshold, the focus motor moves upward 12 steps, if the resolution is less than or equal to 2 / 3 of the set threshold and greater than the setting 1 / 2 of the threshold, then the focus motor moves up 8 steps. If the definition is greater than 2 / 3 of the set threshold, the focus motor moves up 4 steps; and re-judges whether the traversal is completed, traverse After completion, coarse focus is completed, and then fine focus is performed. The present invention can set different thresholds according to the individual differences of each sample to achieve a dynamic sampling step, which not only takes into account the focusing speed, but also ensures that the optimal focal length will not be missed.

Description

technical field [0001] The invention relates to the technical field of image analysis, in particular to an automatic focusing method. Background technique [0002] Urine examination has become a widely used clinical examination method because of its simplicity, quickness, and easy access to specimens, and it is one of the current routine clinical examination items in hospitals. [0003] At present, there are mainly two types of technologies for urine sediment detectors that have been applied clinically: one uses flow cytometry and electrical impedance measurement. Its working principle is mainly to put the cells to be tested into the sample tube after being stained with specific fluorescent dyes, and enter the flow chamber filled with sheath fluid under the pressure of the gas. Under the confinement of the sheath fluid, the cells are arranged in a single row and ejected from the nozzle of the flow chamber to form a cell column, which intersects the incident laser beam perpe...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the purpose of the present invention is to provide a method for autofocusing, aiming at the urine formed component analyzer focusing on the existing grid (the grid-shaped interlaced lines engraved on the counting pool for determining the focal plane) The stability and accuracy of the autofocus function in real use scenarios, the proposed autofocus algorithm based on image analysis

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