Iterative reconstruction in image formation

An image formation system for use in iterative reconstruction, comprising:

• a processing component configured to access acquired data from an imaging device;
• and
• a memory configured to store one or more routines which, when executed by the processor, cause acts to be performed comprising:
• generating an image estimate;
• simulating an expected projection based on the image estimate;
• comparing the expected projection to the acquired projection data based on noise characteristics;
• determining a gradient vector based on the cost function;
• implementing a multi-channel preconditioner on two or more channels such that each channel is processed independent of the other channels;
• combining the outputs of the multi-channel preconditioner to generate a transformed gradient vector;
• and
• updating the image estimate using the transformed gradient vector.

One or more non-transitory computer-readable media encoding routines which, when executed, cause acts to be performed comprising:

• generating an image estimate;
• simulating an expected projection based on the image estimate;
• comparing the expected projection to a set of measured projection data acquired by an imaging system based on a set of noise characteristics;
• determining a gradient vector based on the cost function;
• implementing a multi-channel preconditioner on two or more channels such that each channel is processed independent of the other channels;
• applying the multi-channel preconditioner to the gradient vector;
• combining the outputs of the multi-channel preconditioner to generate a transformed gradient vector;
• and
• updating the image estimate using the transformed gradient vector.