function vt_initial(imgType, varargin)

%% initial some variables

% define a variable of visual template

global VT;

% define the number of visual templates

global NUM_VT;

NUM_VT = 1;

% define a variable of previous vt id

global PREV_VT_ID;

PREV_VT_ID = 1;

% define history of visual template

global VT_HISTORY;

global VT_HISTORY_FIRST;

global VT_HISTORY_OLD;

VT_HISTORY = [0];

% for showing the comparing result between current imgs with templates

global MIN_DIFF_CURR_IMG_VTS;

MIN_DIFF_CURR_IMG_VTS = [0];

global DIFFS_ALL_IMGS_VTS;

DIFFS_ALL_IMGS_VTS = [0];

% define a variable for showing sub vt imgage

global SUB_VT_IMG;

global IMG_TYPE;

%% Process the parameters

% parser some pameters

% define the threshold for vt matching

% This threshold determines whether a new view template is generated

global VT_MATCH_THRESHOLD;

% define the x, y range of visual template img

global VT_IMG_CROP_Y_RANGE; % Row range

global VT_IMG_CROP_X_RANGE; % Column range

% Define resized range of visual template img for reducing resolution

global VT_IMG_RESIZE_X_RANGE;

global VT_IMG_RESIZE_Y_RANGE;

% define x, y shift range for template matching

% This determines how many +- pixels (therefore rotation) will be tested for match

global VT_IMG_X_SHIFT;

global VT_IMG_Y_SHIFT;

% define decay of vt for updating vts

% VT_GLOBAL_DECAY is subtracted for all the view templates at each time step

% VT_ACTIVE_DECAY is added the best matching view template

global VT_GLOBAL_DECAY;

global VT_ACTIVE_DECAY;

% define the patch size in x, y for patch normalisation

global PATCH_SIZE_Y_K;

global PATCH_SIZE_X_K;

global BLOCK_READ;

for i=1:(nargin-1)

if ischar(varargin{i})

switch varargin{i}

case 'VT_MATCH_THRESHOLD', VT_MATCH_THRESHOLD = varargin{i+1};

case 'VT_IMG_CROP_Y_RANGE', VT_IMG_CROP_Y_RANGE = varargin{i+1};

case 'VT_IMG_CROP_X_RANGE', VT_IMG_CROP_X_RANGE = varargin{i+1};

case 'VT_IMG_RESIZE_X_RANGE', VT_IMG_RESIZE_X_RANGE = varargin{i+1};

case 'VT_IMG_RESIZE_Y_RANGE', VT_IMG_RESIZE_Y_RANGE = varargin{i+1};

case 'VT_IMG_X_SHIFT', VT_IMG_X_SHIFT = varargin{i+1};

case 'VT_IMG_Y_SHIFT', VT_IMG_Y_SHIFT = varargin{i+1};

case 'VT_GLOBAL_DECAY', VT_GLOBAL_DECAY = varargin{i+1};

case 'VT_ACTIVE_DECAY', VT_ACTIVE_DECAY = varargin{i+1};

case 'PATCH_SIZE_Y_K', PATCH_SIZE_Y_K = varargin{i+1};

case 'PATCH_SIZE_X_K', PATCH_SIZE_X_K = varargin{i+1};

case 'BLOCK_READ', BLOCK_READ = varargin{i+1};

end

end

end

% define half offset for reversed matching

global VT_IMG_HALF_OFFSET;

VT_IMG_HALF_OFFSET = [0 floor(size(VT_IMG_CROP_X_RANGE) / 2)];

%% HDC

% set the initial position in the hdcell network

[curYawTheta, curPitchTheta] = get_hdc_initial_theta();

%% GC

% set the initial position in the grid cell network

[gcX, gcY, gcZ] = get_gc_initial_pos();

VT(1).id = 1;

VT(1).template(1) = 1;

VT(1).decay = 0.7;

VT(1).gc_x = gcX;

VT(1).gc_y = gcY;

VT(1).gc_z = gcZ;

VT(1).hdc_yaw = curYawTheta;

VT(1).hdc_pitch = curPitchTheta;

VT(1).first = 1; % don't want to inject energy as the vt is been created

VT(1).numExp = 1;

VT(1).exps(1).id = 1;

VT(1).template = zeros(size(VT_IMG_RESIZE_Y_RANGE, 2), size(VT_IMG_RESIZE_X_RANGE, 2));