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- % RES = upConv(IM, FILT, EDGES, STEP, START, STOP, RES)
- %
- % Upsample matrix IM, followed by convolution with matrix FILT. These
- % arguments should be 1D or 2D matrices, and IM must be larger (in
- % both dimensions) than FILT. The origin of filt
- % is assumed to be floor(size(filt)/2)+1.
- %
- % EDGES is a string determining boundary handling:
- % 'circular' - Circular convolution
- % 'reflect1' - Reflect about the edge pixels
- % 'reflect2' - Reflect, doubling the edge pixels
- % 'repeat' - Repeat the edge pixels
- % 'zero' - Assume values of zero outside image boundary
- % 'extend' - Reflect and invert
- % 'dont-compute' - Zero output when filter overhangs OUTPUT boundaries
- %
- % Upsampling factors are determined by STEP (optional, default=[1 1]),
- % a 2-vector [y,x].
- %
- % The window over which the convolution occurs is specfied by START
- % (optional, default=[1,1], and STOP (optional, default =
- % step .* (size(IM) + floor((start-1)./step))).
- %
- % RES is an optional result matrix. The convolution result will be
- % destructively added into this matrix. If this argument is passed, the
- % result matrix will not be returned. DO NOT USE THIS ARGUMENT IF
- % YOU DO NOT UNDERSTAND WHAT THIS MEANS!!
- %
- % NOTE: this operation corresponds to multiplication of a signal
- % vector by a matrix whose columns contain copies of the time-reversed
- % (or space-reversed) FILT shifted by multiples of STEP. See corrDn.m
- % for the operation corresponding to the transpose of this matrix.
- % Eero Simoncelli, 6/96. revised 2/97.
- function result = upConv(im,filt,edges,step,start,stop,res)
- %% THIS CODE IS NOT ACTUALLY USED! (MEX FILE IS CALLED INSTEAD)
- fprintf(1,'WARNING: You should compile the MEX version of "upConv.c",\n found in the MEX subdirectory of matlabPyrTools, and put it in your matlab path. It is MUCH faster, and provides more boundary-handling options.\n');
- %------------------------------------------------------------
- %% OPTIONAL ARGS:
- if (exist('edges') == 1)
- if (strcmp(edges,'reflect1') ~= 1)
- warning('Using REFLECT1 edge-handling (use MEX code for other options).');
- end
- end
- if (exist('step') ~= 1)
- step = [1,1];
- end
- if (exist('start') ~= 1)
- start = [1,1];
- end
- % A multiple of step
- if (exist('stop') ~= 1)
- stop = step .* (floor((start-ones(size(start)))./step)+size(im))
- end
- if ( ceil((stop(1)+1-start(1)) / step(1)) ~= size(im,1) )
- error('Bad Y result dimension');
- end
- if ( ceil((stop(2)+1-start(2)) / step(2)) ~= size(im,2) )
- error('Bad X result dimension');
- end
- if (exist('res') ~= 1)
- res = zeros(stop-start+1);
- end
- %------------------------------------------------------------
- tmp = zeros(size(res));
- tmp(start(1):step(1):stop(1),start(2):step(2):stop(2)) = im;
- result = rconv2(tmp,filt) + res;
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