Method and apparatus for processing image data in an x-ray imaging system

An apparatus for performing image data processing in an X-ray imaging system, the X-ray imaging system having a collimator for collimating an incident direction of X-rays with respect to an X-ray detector, the apparatus comprising:

• processing circuitry configured to
• obtain a two-dimensional (2D) projection image acquired by the X-ray imaging system;
• and
• input the obtained 2D projection image into a pretrained machine-learning model, to infer a 2D projection image from an output of the pretrained machine-learning model, the inferred 2D projection image having an image quality better than an image quality of the obtained 2D projection image, wherein
• the pretrained machine-learning model is trained on a plurality of training images, each training image of the plurality of training images being obtained by:
• receiving a first 2D projection image acquired by an X-ray imaging system under a condition that no collimator is applied for X-ray collimation,
• determining a collimator simulation parameter,
• estimating a scatter field for the first 2D projection image, generating a noise-simulating image based on the estimated scatter field, and generating a penumbra-simulating image to simulate a penumbra caused by a collimator, based on the determined collimator simulation parameter, and
• generating a second 2D projection image, as the training image, by combining the noise-simulating image, the penumbra-simulating image, and the first 2D projection image.