Systems and methods for image processing

A method implemented on a machine having one or more processors and one or more storage devices, comprising:

• obtaining an image representing a region of interest (ROI) of an object, the ROI including two or more sub-regions, the image being generated based on imaging signals corresponding to the ROI;
• determining an average value of quantitative indexes associated with elements in the image corresponding to a first region of the ROI;
• for each of the two or more sub-regions of the ROI, determining a threshold based on the average value, the thresholds of at least two of the two or more sub-regions being different;
• identifying target elements in the image based on the thresholds of the two or more sub-regions, the quantitative index of each of the target elements being equal to or larger than the threshold of the corresponding sub-region;
• assigning a presentation value to each of at least some of the target elements based on the average value and the quantitative index of the each target element;
• and
• generating a presentation of the image based on the presentation values.

A non-transitory computer readable medium, comprising at least one set of instructions, wherein when executed by one or more processors of a computing device, the at least one set of instructions causes the computing device to perform a method, the method comprising:

• obtaining an image representing a region of interest (ROI) of an object, the ROI including two or more sub-regions, the image being generated based on imaging signals corresponding to the ROI;
• determining an average value of quantitative indexes associated with elements in the image corresponding to a first region of the ROI;
• for each of the two or more sub-regions of the ROI, determining a threshold based on the average value, the thresholds of at least two of the two or more sub-regions being different;
• identifying target elements in the image based on the thresholds of the two or more sub-regions, the quantitative index of each of the target elements being equal to or larger than the threshold of the corresponding sub-region;
• assigning a presentation value to each of at least some of the target elements based on the average value and the quantitative index of the each target element;
• and
• generating a presentation of the image based on the presentation values.