# acfModify

## PURPOSE

Modify aggregate channel features object detector.

## SYNOPSIS

function detector = acfModify( detector, varargin )

## DESCRIPTION

     Modify aggregate channel features object detector.

     Takes an object detector trained by acfTrain() and modifies it. Only
     certain modifications are allowed to the detector and the detector should
     never be modified directly (this may cause the detector to be invalid and
     cause segmentation faults). Any valid modification to a detector after it
     is trained should be performed using acfModify().

     The parameters 'nPerOct', 'nOctUp', 'nApprox', 'lambdas', 'pad', 'minDs'
     modify the channel feature pyramid created (see help of chnsPyramid.m for
     more details) and primarily control the scales used. The parameters
     'pNms', 'stride', 'cascThr' and 'cascCal' modify the detector behavior
     (see help of acfTrain.m for more details). Finally, 'rescale' can be
     used to rescale the trained detector (this change is irreversible).

     USAGE
      detector = acfModify( detector, pModify )

     INPUTS
      detector   - detector trained via acfTrain
      pModify    - parameters (struct or name/value pairs)
       .nPerOct    - [] number of scales per octave
       .nOctUp     - [] number of upsampled octaves to compute
       .nApprox    - [] number of approx. scales to use
       .lambdas    - [] coefficients for power law scaling (see BMVC10)
       .pad        - [] amount to pad channels (along T/B and L/R)
       .minDs      - [] minimum image size for channel computation
       .pNms       - [] params for non-maximal suppression (see bbNms.m)
       .stride     - [] spatial stride between detection windows
       .cascThr    - [] constant cascade threshold (affects speed/accuracy)
       .cascCal    - [] cascade calibration (affects speed/accuracy)
       .rescale    - [] rescale entire detector by given ratio

     OUTPUTS
      detector   - modified object detector

     EXAMPLE

     See also chnsPyramid, bbNms, acfTrain, acfDetect

     Piotr's Image&Video Toolbox      Version 3.20
     Copyright 2013 Piotr Dollar & Ron Appel.  [pdollar-at-caltech.edu]
     Please email me if you find bugs, or have suggestions or questions!
     Licensed under the Simplified BSD License [see external/bsd.txt]