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- function imo = cnn_ucf101_get_frame_batch(images, varargin)
-
- opts.nFramesPerVid = 1;
- opts.numAugments = 1;
- opts.frameSample = 'uniformly';
- opts.uniformAugments = false;
- opts.imageDir = '';
- opts.temporalStride = 0;
-
- opts.imageSize = [227, 227] ;
- opts.border = [29, 29] ;
- opts.averageImage = [] ;
- opts.rgbVariance = [] ;
-
- opts.augmentation = 'croponly' ;
- opts.interpolation = 'bilinear' ;
- opts.numAugments = 1 ;
- opts.numThreads = 0 ;
- opts.prefetch = false ;
- opts.keepAspect = true;
- opts.cheapResize = 0;
- opts.frameList = NaN;
- opts.nFrames = [];
- opts.imReadSz = [];
- opts.stretchAspect = 4/3 ;
- opts.stretchScale = 1.2 ;
- [opts, varargin] = vl_argparse(opts, varargin);
-
- imgDir = opts.imageDir;
-
- prefetch = opts.prefetch & isempty(opts.frameList);
-
- switch opts.augmentation
- case 'randCropFlip'
- 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(0,1,50)) ;
- tfs = [tx(:)' ; ty(:)' ; zeros(1,numel(tx))] ;
- tfs_ = tfs ;
- tfs_(3,:) = 1 ;
- tfs = [tfs,tfs_] ;
- case 'borders25'
- [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_] ;
- case 'borders'
- opts.imReadSz(1) = 224 + (342-224).*rand();
- opts.imReadSz(2) = 300 + (480-300).*rand();
- opts.cheapResize = true;
-
- otherwise
- opts.imReadResize = 0;
-
- end
-
- if iscell(opts.frameList)
- if isempty(opts.imReadSz)
- im = vl_imreadjpeg(opts.frameList{1}, 'numThreads', opts.numThreads ) ;
- else
- im = vl_imreadjpeg(opts.frameList{1}, 'numThreads', opts.numThreads, 'resize', opts.imReadSz ) ;
- end
- sampled_frame_nr = opts.frameList{2};
- else
- sampled_frame_nr = cell(numel(images),1);
- frames = cell(numel(images), opts.nFramesPerVid);
- for i=1:numel(images)
- vid_name = images{i};
- nFrames = opts.nFrames(i);
- if strcmp(opts.frameSample, 'uniformly')
- sampleRate = max(floor((nFrames)/opts.nFramesPerVid),1);
- frameSamples =1:sampleRate:nFrames ;
- elseif strcmp(opts.frameSample, 'temporalStride')
- shift = floor(mod(nFrames,opts.temporalStride)/2); % shift to centre of long videos
- frameSamples = 1:opts.temporalStride:nFrames;
- elseif strcmp(opts.frameSample, 'random')
- frameSamples = randperm(nFrames);
- elseif strcmp(opts.frameSample, 'temporalStrideRandom')
- sampleStart = randi(opts.temporalStride) ;
- frameSamples = sampleStart:opts.temporalStride:nFrames;
- if isempty(frameSamples)
- frameSamples = 1:opts.temporalStride:nFrames;
- end
- end
- if length(frameSamples) < opts.nFramesPerVid,
- diff = opts.nFramesPerVid - length(frameSamples);
- frameSamples = padarray(frameSamples,[0 diff],'symmetric','post');
- elseif length(frameSamples) > opts.nFramesPerVid,
- s = randi(length(frameSamples)-opts.nFramesPerVid);
- frameSamples = frameSamples(s:s+opts.nFramesPerVid-1);
- end
-
- for k = 1:opts.nFramesPerVid
- frames{i,k} = fullfile(vid_name, ['frame' sprintf('%06d.jpg', frameSamples(k))]) ;
- end
-
- if iscell(opts.imageDir)
- imgDir = opts.imageDir{i};
- end
-
- frames(i,1:opts.nFramesPerVid) = strcat([imgDir filesep], frames(i,1:opts.nFramesPerVid));
- sampled_frame_nr{i} = frameSamples;
-
- end
-
- if opts.numThreads > 0
- if prefetch
- if isempty(opts.imReadSz)
- vl_imreadjpeg(frames, 'numThreads', opts.numThreads, 'prefetch' ) ;
- else
- vl_imreadjpeg(frames, 'numThreads', opts.numThreads, 'prefetch', 'resize', opts.imReadSz ) ;
- end
- imo = {frames sampled_frame_nr} ;
- return ;
- end
- if isempty(opts.imReadSz)
- im = vl_imreadjpeg(frames, 'numThreads', opts.numThreads) ;
- else
- im = vl_imreadjpeg(frames, 'numThreads', opts.numThreads, 'resize', opts.imReadSz ) ;
- end
- end
- end
-
- %% no augm
- 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), ...
- 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
- im{i,k} = im{i,k}(1:h_min,1:w_min,:);
- 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,:);
- 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), ...
- numel(images), opts.numAugments * opts.nFramesPerVid, 'single') ) ;
-
-
- szw = cellfun(@(x) size(x,2),im);
- szh = cellfun(@(x) size(x,1),im);
-
- for i=1:numel(images)
- si = 1 ;
-
-
- h_min = min(szh(:));
- w_min = min(szw(:));
-
- if strcmp( opts.augmentation, 'borders25')
- sz = round(min(opts.imageSize(1:2)' .* (.75+0.5*rand(2,1)), [h_min; w_min])) ; % 0.75 +- 0.5, not keep aspect
- elseif strcmp( opts.augmentation, 'stretch')
- aspect = exp((2*rand-1) * log(opts.stretchAspect)) ;
- scale = exp((2*rand-1) * log(opts.stretchScale)) ;
- tw = opts.imageSize(2) * sqrt(aspect) * scale ;
- th = opts.imageSize(1) / sqrt(aspect) * scale ;
- reduce = min([w_min / tw, h_min / th, 1]) ;
- sz = round(reduce * [th ; tw]) ;
- else
- sz(1) = round(160 + (256-160).*rand());
- sz(2) = round(160 + (256-160).*rand());
- end
-
- for k = 1:opts.nFramesPerVid
- imt = im{i,k} ;
- w = size(imt,2) ;
- h = size(imt,1) ;
- if ~strcmp(opts.augmentation, 'uniform')
- if ~isempty(opts.rgbVariance)
- opts.averageImage = bsxfun(@plus, opts.averageImage, reshape(opts.rgbVariance * randn(opts.imageSize(3),1), 1,1,opts.imageSize(3))) ;
- end
- for ai = 1:opts.numAugments
- if k == 1
- switch opts.augmentation
- case 'stretch'
- dx = randi(w - sz(2) + 1 ) ;
- dy = randi(h - sz(1) + 1 ) ;
- flip = rand > 0.5 ;
- case 'multiScaleRegular'
- dy = [0 h-sz(1) 0 h-sz(1) floor((h-sz(1)+1)/2)] + 1;
- dx = [0 w-sz(2) w-sz(2) 0 floor((w-sz(2)+1)/2)] + 1;
- corner = randi(5);
- dx = dx(corner); dy = dy(corner);
- flip = rand > 0.5 ;
- case 'borders25'
- 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) ;
- case 'borders'
- randx = rand > 0.5 ;
- if randx
- top = rand > 0.5 ;
- dx = randi(w - sz(2) + 1 ) ;
- dy = floor((h - sz(1)) * top) + 1 ;
- else
- right = rand > 0.5 ;
- dx = floor((w - sz(2)) * right) + 1 ;
- dy = randi(h - sz(1) + 1 ) ;
- end
- flip = rand > 0.5 ;
- otherwise
- 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
- 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,:) ;
- else
- imo(:,:,:,i,si) = imt(sy,sx,:) ;
- end
-
- si = si + 1 ;
- end
- else
- % oversample (4 corners, center, and their x-axis flips)
- 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);
-
- 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);
-
- si = si + 2;
-
- end
- end
- end
-
- if ~isempty(opts.averageImage)
- imo = bsxfun(@minus, imo, opts.averageImage) ;
- end
- end
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