System and method for reconstructing an image

A method implemented on a computing device having at least one processor, at least one computer-readable storage medium, and a communication port connected to an imaging device, the method comprising:

• obtaining image data, wherein the image data includes projection data and is generated by the imaging device;
• determining an objective function associated with a target image based on the image data, the objective function including a first model and a regularization item for denoising the image data, wherein the first model represents a difference between a projection of the target image and the image data, and wherein the regularization item includes a denoising model and a second model for adjusting an intensity of denoising the image data, the second model is determined based on a weighting matrix, and the weighting matrix is determined based on an extended Tam window;
• and
• reconstructing the target image by performing a plurality of iterations based on the objective function.

A system, comprising:

• at least one non-transitory computer-readable storage medium including a set of instructions;
• at least one processor in communication with the at least one non-transitory computer-readable storage medium, wherein when executing the instructions, the at least one processor is configured to cause the system to:
• obtain image data, wherein the image data includes projection data and is generated by a detector array;
• determine a weighting window based on parameters relating to the detector array, wherein the parameters relating to the detector array include a first count of the detector units in the row direction and a second count of the detector units in the channel direction, and the weighting window corresponds to an extended Tam window;
• determine a first set of data based on the image data and the weighting window;
• determine an objective function associated with a target image based on the first set of data, the objective function including a first model and a regularization item for denoising the image data, wherein the first model represents a difference between a projection of the target image and the first set of data, and the first model is identified based on the first set of data, and wherein the regularization item includes a denoising model and a second model for adjusting an intensity of denoising the image data, the second model is determined based on a weighting matrix, and the weighting matrix is determined based on the extended Tam window;
• and
• reconstruct the target image by performing a plurality of iterations based on the objective function.