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- function imo = cnn_ucf101_get_im_flow_batch(images, varargin)
-
- opts.nFramesPerVid = 1;
- opts.numAugments = 1;
- opts.frameSample = 'uniformly';
- opts.flowDir = '';
- opts.imageDir = '';
- opts.temporalStride = 0;
- opts.imageSize = [224, 224] ;
- opts.border = [32, 32] ;
- opts.averageImage = [] ;
- opts.rgbVariance = [] ;
- opts.augmentation = 'croponly' ;
- opts.interpolation = 'bilinear' ;
- opts.numAugments = 1 ;
- opts.numThreads = 1 ;
- opts.prefetch = false ;
- opts.keepAspect = true;
- opts.cheapResize = 0;
- opts.nFrameStack = 10;
- opts.frameList = NaN;
- opts.nFrames = [];
- [opts, varargin] = vl_argparse(opts, varargin);
-
- flowDir = opts.flowDir;
- imgDir = opts.imageDir;
- % prefetch is used to load images in a separate thread
- prefetch = opts.prefetch & isempty(opts.frameList);
-
- switch opts.augmentation
- case 'croponly'
- tfs = [.5 ; .5 ; 0 ];
- case 'f5'
- tfs = [...
- .5 0 0 1 1 .5 0 0 1 1 ;
- .5 0 1 0 1 .5 0 1 0 1 ;
- 0 0 0 0 0 1 1 1 1 1] ;
- case 'f25'
- [tx,ty] = meshgrid(linspace(0,1,5)) ;
- tfs = [tx(:)' ; ty(:)' ; zeros(1,numel(tx))] ;
- tfs_ = tfs ;
- tfs_(3,:) = 1 ;
- tfs = [tfs,tfs_] ;
- case 'noCtr'
- [tx1,ty1] = meshgrid(linspace(.75,1,20)) ;
- [tx2,ty2] = meshgrid(linspace(0,.25,20)) ;
- tx = [tx1 tx2]; ty = [ty1 ty2];
- tfs = [tx(:)' ; ty(:)' ; zeros(1,numel(tx))] ;
- tfs_ = tfs ;
- tfs_(3,:) = 1 ;
- tfs = [tfs,tfs_] ;
- end
-
- nStack = opts.imageSize(3);
-
- if iscell(opts.frameList)
- im = vl_imreadjpeg(opts.frameList{1}, 'numThreads', opts.numThreads) ;
- sampled_frame_nr = opts.frameList{2};
- else
- sampleFrameLeftRight = floor(nStack/4); % divide by 4 because of left,right,u,v
- frameOffsets = [-sampleFrameLeftRight:sampleFrameLeftRight-1]';
- frames = cell(numel(images), nStack, opts.nFramesPerVid);
- frames_rgb = cell(numel(images), 1, opts.nFramesPerVid);
- sampled_frame_nr = cell(numel(images),1);
-
-
- for i=1:numel(images)
- vid_name = images{i};
- nFrames = opts.nFrames(i);
- if strcmp(opts.frameSample, 'uniformly')
- sampleRate = max(floor((nFrames-nStack/2)/opts.nFramesPerVid),1);
- opts.temporalStride = sampleRate;
- frameSamples = vl_colsubset(nStack/4+1:nFrames-nStack/4, opts.nFramesPerVid, 'uniform') ;
- elseif strcmp(opts.frameSample, 'temporalStride')
- frameSamples = nStack/4+1:opts.temporalStride:nFrames-nStack/4 ;
- if length(frameSamples) < opts.nFrameStack,
- frameSamples = round(linspace(nStack/4+1, nFrames - nStack/4, opts.nFrameStack)) ;
- opts.temporalStride = frameSamples(2) - frameSamples(1);
- end
- elseif strcmp(opts.frameSample, 'random')
- frameSamples = randperm(nFrames-nStack/2)+nStack/4;
- elseif strcmp(opts.frameSample, 'temporalStrideRandom')
- frameSamples = nStack/4 +1:opts.temporalStride:nFrames - nStack/4 ;
- end
-
- if length(frameSamples) < opts.nFramesPerVid,
- if length(frameSamples) > opts.nFrameStack
- frameSamples = frameSamples(1:length(frameSamples)-mod(length(frameSamples),opts.nFrameStack));
- end
- diff = opts.nFramesPerVid - length(frameSamples);
-
- addFrames = 0;
- while diff > 0
- last_frame = min(frameSamples(end), max(nFrames - nStack/4 - opts.nFrameStack,nStack/4 ));
- if mod(addFrames,2) % add to the front
- addSamples = nStack/4+1:opts.temporalStride:nFrames - nStack/4;
- addSamples = addSamples(1: length(addSamples) - mod(length(addSamples),opts.nFrameStack));
- if length(addSamples) > diff, addSamples = addSamples(1:diff); end
- else % add to the back
- addSamples = fliplr(nFrames - nStack/4 : -opts.temporalStride: nStack/4+1);
- addSamples = addSamples(mod(length(addSamples),opts.nFrameStack)+1:length(addSamples));
- if length(addSamples) > diff, addSamples = addSamples(end-diff+1:end); end
- end
-
- if addFrames > 20,
- addSamples = round(linspace(nStack/4+1, nFrames - nStack/4, opts.nFrameStack)) ;
- end
- frameSamples = [frameSamples addSamples];
- diff = opts.nFramesPerVid - length(frameSamples);
- opts.temporalStride = max(ceil(opts.temporalStride-1), 1);
- addFrames = addFrames+1;
- end
- end
- if length(frameSamples) > opts.nFramesPerVid
- s = randi(length(frameSamples)-opts.nFramesPerVid);
- frameSamples = frameSamples(s+1:s+opts.nFramesPerVid);
- end
-
- for k = 1:opts.nFramesPerVid
- frames_rgb{i,1,k} = [vid_name 'frame' sprintf('%06d.jpg', frameSamples(k))] ;
- end
- frameSamples = repmat(frameSamples,nStack/2,1) + repmat(frameOffsets,1,size(frameSamples,2));
- for k = 1:opts.nFramesPerVid
- for j = 1:nStack/2
- frames{i,(j-1)*2+1, k} = ['u' filesep vid_name 'frame' sprintf('%06d.jpg', frameSamples(j,k)) ] ;
- frames{i,(j-1)*2+2, k} = ['v' frames{i,(j-1)*2+1, k}(2:end)];
- end
- end
- sampled_frame_nr{i} = frameSamples;
- end
-
- frames_rgb = strcat([imgDir filesep], frames_rgb);
- if ~isempty(flowDir)
- frames = strcat([flowDir filesep], frames);
- frames = cat(2, frames, frames_rgb);
- else
- frames = frames_rgb;
- end
-
- if opts.numThreads > 0
- if prefetch
- vl_imreadjpeg(frames, 'numThreads', opts.numThreads, 'prefetch') ;
- imo = {frames sampled_frame_nr} ;
- return ;
- end
- im = vl_imreadjpeg(frames, 'numThreads', opts.numThreads) ;
- end
- end
-
- if strcmp(opts.augmentation, 'none')
- szw = cellfun(@(x) size(x,2),im);
- szh = cellfun(@(x) size(x,1),im);
-
- h_min = min(szh(:));
- w_min = min(szw(:));
- sz = [h_min w_min] ;
- sz = max(opts.imageSize(1:2), sz);
- sz = min(2*opts.imageSize(1:2), sz);
- scal = ([h_min w_min] ./ sz);
-
- imo = ( zeros(sz(1), sz(2), opts.imageSize(3)+3, ...
- numel(images), 2 * opts.nFramesPerVid, 'single') );
-
- for i=1:numel(images)
- si = 1 ;
- for k = 1:opts.nFramesPerVid
- if numel(unique(szw)) > 1 || numel(unique(szh)) > 1
- for l=1:size(im,2)
- im{i,l,k} = im{i,l,k}(1:h_min,1:w_min,:);
- end
- end
- imt = cat(3, im{i,:,k}) ;
- if any(scal ~= 1)
- imt = imresize(imt, sz );
- end
- imo(:, :, :, i, si) = imt;
- imo(:, :, :, i, si+1) = imt(:, end:-1:1,:);
- imo(:, :, 1:2:nStack, i, si+1) = -imt(:, end:-1:1, 1:2:nStack) + 255; %invert u if we flip
- si = si + 2 ;
- end
- end
-
- if ~isempty(opts.averageImage)
- opts.averageImage = mean(mean(opts.averageImage,1),2) ;
- imo = bsxfun(@minus, imo,opts.averageImage) ;
- end
- return;
- end
-
- % augment now
- if exist('tfs', 'var')
- [~,transformations] = sort(rand(size(tfs,2), numel(images)*opts.nFramesPerVid), 1) ;
- end
-
- imo = ( zeros(opts.imageSize(1), opts.imageSize(2), opts.imageSize(3)+3, ...
- numel(images), opts.numAugments * opts.nFramesPerVid, 'single') ) ;
- for i=1:numel(images)
- si = 1 ;
- szw = cellfun(@(x) size(x,2),im);
- szh = cellfun(@(x) size(x,1),im);
- h_min = min(szh(:));
- w_min = min(szw(:));
-
- sz = round(min(opts.imageSize(1:2)' .* (.75+0.5*rand(2,1)), [h_min; w_min])) ; % 0.75 +- 0.5, not keep aspect
- for k = 1:opts.nFramesPerVid
- if numel(unique(szw)) > 1 || numel(unique(szh)) > 1
- for l=1:size(im,2)
- im{i,l,k} = im{i,l,k}(1:h_min,1:w_min,:);
- end
- end
- imt = cat(3, im{i,:,k}) ;
- w = size(imt,2) ;
- h = size(imt,1) ;
- if ~strcmp(opts.augmentation, 'uniform')
- if ~isempty(opts.rgbVariance) % colour jittering only in training case
- offset = zeros(size(imt));
- offset = bsxfun(@minus, offset, reshape(opts.rgbVariance * randn(opts.imageSize(3),1), 1,1,opts.imageSize(3))) ;
- imt = bsxfun(@minus, imt, offset) ;
- end
-
- for ai = 1:opts.numAugments
- switch opts.augmentation
- case 'randCropFlip'
- sz = opts.imageSize(1:2) ;
- dx = randi(w - sz(2) + 1 ) ;
- dy = randi(h - sz(1) + 1 ) ;
- flip = rand > 0.5 ;
- case 'noCtr'
- tf = tfs(:, transformations(mod(i+ai-1, numel(transformations)) + 1)) ;
- dx = floor((w - sz(2)) * tf(2)) + 1 ;
- dy = floor((h - sz(1)) * tf(1)) + 1 ;
- flip = tf(3) ;
- otherwise
- sz = opts.imageSize(1:2) ;
- tf = tfs(:, transformations(mod(ai-1, numel(transformations)) + 1)) ;
- dx = floor((w - sz(2)) * tf(2)) + 1 ;
- dy = floor((h - sz(1)) * tf(1)) + 1 ;
- flip = tf(3) ;
- end
-
- if opts.cheapResize
- sx = round(linspace(dx, sz(2)+dx-1, opts.imageSize(2))) ;
- sy = round(linspace(dy, sz(1)+dy-1, opts.imageSize(1))) ;
- else
- factor = [opts.imageSize(1)/sz(1) ...
- opts.imageSize(2)/sz(2)];
- if any(abs(factor - 1) > 0.0001)
- imt = imresize(gather(imt(dy:sz(1)+dy-1,dx:sz(2)+dx-1,:)), [opts.imageSize(1:2)]);
- end
- sx = 1:opts.imageSize(2); sy = 1:opts.imageSize(1);
- end
-
- if flip
- sx = fliplr(sx) ;
- imo(:,:,:,i,si) = imt(sy,sx,:) ;
- imo(:,:,1:2:nStack,i,si) = -imt(sy,sx,1:2:nStack) + 255; %invert u if we flip
- else
- imo(:,:,:,i,si) = imt(sy,sx,:) ;
- end
-
- si = si + 1 ;
- end
- else
- % sample (4 corners, center, and their x-axis flips)
- w = size(imt,2) ; h = size(imt,1) ;
- indices_y = [0 h-opts.imageSize(1)] + 1;
- indices_x = [0 w-opts.imageSize(2)] + 1;
- center_y = floor(indices_y(2) / 2)+1;
- center_x = floor(indices_x(2) / 2)+1;
- if opts.numAugments == 6, indices_y = center_y;
- elseif opts.numAugments == 2, indices_x = []; indices_y = [];
- elseif opts.numAugments ~= 10, error('only 6 or 10 uniform crops allowed');
- end
- for y = indices_y
- for x = indices_x
- imo(:, :, :, i, si) = ...
- imt(y:y+opts.imageSize(1)-1, x:x+opts.imageSize(2)-1, :);
- imo(:, :, :, i, si+1) = imo(:, end:-1:1, :, i, si);
- imo(:, :, 1:2:nStack, i, si+1) = -imo(:, end:-1:1, 1:2:nStack, i, si) + 255; %invert u if we flip
- si = si + 2 ;
- end
- end
- imo(:,:,:, i,si) = imt(center_y:center_y+opts.imageSize(1)-1,center_x:center_x+opts.imageSize(2)-1,:);
- imo(:,:,:, i,si+1) = imo(:, end:-1:1, :, i, si);
- imo(:,:,1:2:nStack, i,si+1) = -imo(:, end:-1:1, 1:2:nStack, i, si) + 255; %invert u if we flip
- si = si + 2;
- end
- end
- end
-
- if ~isempty(opts.averageImage)
- imo = bsxfun(@minus, imo, opts.averageImage) ;
- end
-
- end
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