midprocess
A midprocess performs the delay-and-sum operation, transforming channel data into beamformed data. The number of output pixels is determined by a scan grid object.
channel_data → Output: beamformed_data- class das
DAS Generalized Delay-And-Sum beamformer
DAS implements the Generalized Beamformer described in Eq. (2) of the reference paper. It computes pixel values by delaying and summing channel data according to round-trip propagation times.
- The dimension property controls which summation is performed:
dimension.receive - sum over Rx channels, Eq. (24) dimension.transmit - sum over Tx events, Eq. (26) dimension.both - sum over both Rx and Tx, Eq. (2) dimension.none - return delayed data without summation
- Properties:
dimension DIMENSION (default: dimension.both) code CODE implementation selector (default: code.mex) gpu_id CUDA GPU device id (for GPU implementations) spherical_transmit_delay_model model for focused Tx delay calculation pw_margin margin for hybrid delay model [m] lens_delay additional receive delay offset [s] elapsed_time execution time of last go() call [s]
- Inherited from midprocess:
channel_data UFF.CHANNEL_DATA input scan UFF.SCAN pixel grid receive_apodization UFF.APODIZATION Rx weighting, w_m^Rx(x), Eq. (22) transmit_apodization UFF.APODIZATION Tx weighting, w_a^Tx(x), Eq. (23)
- Example:
mid = midprocess.das(); mid.channel_data = channel_data; mid.scan = scan; mid.dimension = dimension.both; b_data = mid.go();
See also MIDPROCESS, DIMENSION, CODE, SPHERICAL_TRANSMIT_DELAY_MODEL
- References:
Rindal et al., “The Generalized Beamformer”, TechRxiv preprint, https://www.techrxiv.org/users/684320/articles/1263073-the-generalized-beamformer-in-the-ultrasound-toolbox
- Property Summary
- code
Code enumeration class that specifies the code to be run (code.matlab, code.mex, …)
- dimension
Dimension enumeration class that specifies whether the process will run only on transmit, receive, both, or none.
- elapsed_time
Variable to store the beamforming time. Used for benchmarking
- gpu_id
In case code.matlab_gpu or code.mex_gpu is used, this variable specfifies which CUDA-enabled gpu the code should run on
- lens_delay
Additional delay added to the receive delay
- pw_margin
The margin of the area around focus in m for the spherical_transmit_delay_model.hybrid
- receive_delay
Variable returning the calculated rx part of the receive delay so that it can be plotted
- spherical_transmit_delay_model
spherical transmit delay model enumeration for deciding model when the source is in front of the transducer
- transmit_delay
Variable returning the calculated tx part of the receive delay so that it can be plotted
- Method Summary
- go(h)
short names