Measuring method and measuring apparatus of blood vessel diameter of fundus image

A apparatus for measuring a blood vessel diameter of a fundus image, the apparatus comprising:

• an acquisition unit configured to acquire the fundus image including the blood vessel;
• a segmentation unit configured to generating a blood vessel segmentation image based on the fundus image;
• an enhancement unit configured to perform resolution enhancement on the blood vessel segmentation image according to a preset multiple to generate an enhanced blood vessel segmentation image;
• an extraction unit configured to extract blood vessel skeletons from the enhanced blood vessel segmentation image and to perform fitting on the blood vessel skeletons to obtain a continuous blood vessel skeleton and a vessel diameter measurement direction of measurement pixel points, the measurement pixel points being a plurality of pixel points on the continuous blood vessel skeleton and the vessel diameter measurement direction being perpendicular to a tangent line of the continuous blood vessel skeleton on the measurement pixel points;
• a generation unit configured to generate a blood vessel contour corresponding to the measurement pixel points based on the enhanced blood vessel segmentation image, the measurement pixel points, the vessel diameter measurement direction of the measurement pixel points, and preset precision;
• and
• a calculation unit configured to calculate a blood vessel diameter corresponding to the measurement pixel points based on a number of blood vessel pixel points in the blood vessel contour corresponding to the measurement pixel points, the preset multiple, and the preset precision;
• wherein:
• a blood vessel diameter/corresponding to the measurement pixel points is:
• l=n×s/e,
• wherein:
• n is the number of the blood vessel pixel points in the blood vessel contour corresponding to the measurement pixel points,
• s is the preset precision, and
• e is the preset multiple;
• and
• n is calculated according to following formula:
• n=card({p:p∈P,f(p)>T}),
• wherein:
• p is the measurement pixel points,
• f(p) is pixel values corresponding to the measurement pixel points p,
• T is a preset threshold parameter,
• P is a pixel point set in the blood vessel contour corresponding to the measurement pixel points p, and
• card represents a cardinality of the pixel point set.