function out = landsatdemo(varargin)
%LANDSATDEMO Landsat color composite demo.
%
% This demo allows you to experiment with creating color composites from
% Landsat Thematic Mapper data. Landsat data consists of 7 spectral bands
% that each reveal different features of the region that is imaged. The
% data is read into a 512-by-512-by-7 array. To create a color composite,
% we form an RGB image by assigning spectral bands to red, green, and blue
% intensities.
%
% Try out some common color composites by clicking on the radio
% buttons. The numbers in square brackets map the spectral bands to red,
% green, and blue. The array [3 2 1] means band 3 will be shown as red
% intensities, band 2 will be shown as blue intensities, and band 1 will
% be shown as green intensities.
%
% "True Color [3 2 1]" - shows what our eyes would see from an airplane.
%
% "Near Infrared [4 3 2]" - shows vegetation as red, water as dark.
%
% "Shortwave Infrared [7 4 3]" - shows changes due to moisture.
%
% Click on "Custom Composite", and change the popup menus to create your own
% combinations of red, green, and blue.
%
% Click on "Single Band Intensity" to see individual bands as gray
% intensity images.
%
% Try turning off "Saturation Stretch" by clicking on the checkbox. For
% most Landsat data sets, saturation stretching is important. When
% saturation stretching is turned on, the demo clips 2% of the pixels in
% each band and does a linear contrast stretch before displaying the
% image.
%
% While the demo is running, you can bring the image and data into the
% workspace.
% IMG = LANDSATDEMO('getimage') brings the image into the workspace.
% DATA = LANDSATDEMO('getdata') brings all 7 bands into the workspace.
%
% Note
% ----
% Permission to use Landsat TM data sets provided by Space Imaging,
% LLC, Denver, Colorado.
%
% Example
% -------
% data = landsatdemo('getdata');
% truecolor = data(:,:,[3 2 1]);
% stretched = imadjust(truecolor,stretchlim(truecolor),[]);
% imshow(truecolor), figure, imshow(stretched)
%
% See also IMADJUST, STRETCHLIM.
% Copyright 1993-2002 The MathWorks, Inc.
% $Revision: 1.11 $ $Date: 2002/05/15 18:48:33 $
if (nargin >= 1)
switch varargin{1}
case 'new_image'
new_image
case 'update_radio'
update_radio
case 'update_band'
update_band
case 'display_image'
display_image
case 'getimage'
out = get_image;
case 'getdata'
out = get_data;
otherwise
error('Unrecognized syntax.');
end
else
hfig = DemoFigHandle;
if (isempty(DemoFigHandle))
hfig = create_gui;
set(hfig,'Visible','on');
drawnow
new_image
else
figure(hfig);
end
end
%-------------------------------------------------------
function out = get_image
hfig = DemoFigHandle;
ud = get(hfig,'UserData');
h = ud.h;
if (~isempty(DemoFigHandle))
out = get(h.img,'CData');
else
error('LANDSATDEMO must be running to get an image.');
end
%-------------------------------------------------------
function out = get_data
hfig = DemoFigHandle;
ud = get(hfig,'UserData');
if (~isempty(DemoFigHandle))
out = ud.lan_data;
else
error('LANDSATDEMO must be running to get data.');
end
%-------------------------------------------------------
function new_image
hfig = DemoFigHandle;
ud = get(hfig,'UserData');
h = ud.h;
value = get(h.img_popup, 'Value');
userdata = get(h.img_popup, 'UserData');
if (userdata ~= value) % The selected image really did change
show_busy(hfig);
set(h.img_popup, 'UserData', value);
% Which image has been selected?
img_choices = get(h.img_popup, 'String');
img_choice = img_choices{value};
switch img_choice
case 'Little Colorado River'
lan_filename = 'littlecoriver.lan';
case 'Mississippi River'
lan_filename = 'mississippi.lan';
case 'Montana'
lan_filename = 'montana.lan';
case 'Paris'
lan_filename = 'paris.lan';
case 'Rio de Janeiro'
lan_filename = 'rio.lan';
case 'Tokyo'
lan_filename = 'tokyo.lan';
end
ud.lan_data = lan_read(lan_filename);
set(hfig,'UserData',ud); % add data array to figure userdata
new_composite
end
%-------------------------------------------------------
function new_composite
hfig = DemoFigHandle;
ud = get(hfig,'UserData');
h = ud.h;
show_busy(hfig)
if (get(h.truecolor_radio,'Value') == 1)
bands = [3 2 1];
elseif (get(h.nir_radio,'Value') == 1)
bands = [4 3 2];
elseif (get(h.swir_radio,'Value') == 1)
bands = [7 4 3];
elseif (get(h.custom_radio,'Value') == 1)
red = get(h.red_popup,'Value'); % get bands from popups
green = get(h.green_popup,'Value');
blue = get(h.blue_popup,'Value');
bands = [red green blue];
else
intensity = get(h.intensity_popup,'Value'); % get band from popup
bands = intensity;
end
ud.img_data = ud.lan_data(:,:,bands);
set(hfig,'UserData',ud) % add img_data to userdata
display_image
%-------------------------------------------------------
function display_image
hfig = DemoFigHandle;
ud = get(hfig,'UserData');
h = ud.h;
show_busy(hfig)
% linear saturation stretch
if ( get(h.stretch,'Value') == 1) % stretch
img_data = imadjust(ud.img_data,stretchlim(ud.img_data,[.01 .99]),[]);
else
img_data = ud.img_data; % don't stretch
end
set(h.img,'cdata',img_data)
drawnow
show_ready(hfig)
%-------------------------------------------------------
function update_radio
hfig = gcbf;
ud = get(hfig,'UserData');
h = ud.h;
h_new = gcbo;
% turn enable off when
if (h_new ~= h.custom_radio)
h_custom = [h.red_popup h.green_popup h.blue_popup];
set(h_custom,'Enable','off')
end
if (h_new ~= h.singleband_radio)
set(h.intensity_popup,'Enable','off')
end
h_radios = [h.truecolor_radio h.nir_radio h.swir_radio h.custom_radio ...
h.singleband_radio];
state = get(h_radios,'Value'); % get state after button pressed
state_vec = [state{:}]; % convert cell array to vector
set(h_radios,'Value',0)
set(h_new,'Value',1)
if (length(find(state_vec==1)) > 1) % check if new button was pressed
new_composite
end
%-------------------------------------------------------
function update_band
hfig = gcbf;
h_band = gcbo;
% First, determine if the selected band really changed
value = get(h_band, 'Value');
userdata = get(h_band, 'UserData');
if (userdata ~= value) % The selected band really did change
set(h_band, 'UserData', value);
new_composite
end
%-------------------------------------------------------
function [lan_data] = lan_read(lan_filename)
% LAN_READ Read Landsat data file type .lan
%
fid = fopen(lan_filename,'r');
% find out how big image is based on file size, assume square image, 7 bands
nbands = 7;
fseek(fid,0,'eof');
file_bytes = ftell(fid);
nlines = floor(sqrt(file_bytes/nbands));
nsamples = nlines;
% skip header
nbytes_header = 128;
fseek(fid,nbytes_header,'bof');
% prepend * to read data into an array that has the same class as the data
A = fread(fid,[nsamples nlines*nbands],'*uint8');
fclose(fid);
% put data into a 3D array
A_3dim = reshape(A,nsamples,nbands,nlines);
lan_data = permute(A_3dim,[3 1 2]);
%-------------------------------------------------------
function lowhigh = stretchlim(img,tol)
%STRETCHLIM Find limits to contrast stretch an image.
% LOW_HIGH = STRETCHLIM(I,TOL) returns a pair of intensities that can be
% used by IMADJUST to increase the contrast of an image.
%
% TOL = [LOW_FRACT HIGH_FRACT] specifies the fraction of the image to
% saturate at low and high intensities.
%
nbins = 256;
tol_low = tol(1);
tol_high = tol(2);
[m,n,p] = size(img);
for i = 1:p % Find limits, one plane at a time
N = imhist(img(:,:,i),nbins);
if (length(find(N~=0)) > 1) % check that image is not flat
cdf = cumsum(N)/sum(N);
ilow = min(find(cdf>tol_low));
ihigh = min(find(cdf>=tol_high));
ilowhigh(:,i) = [ilow;ihigh];
else % image is flat
ilowhigh(:,i) = [1; nbins];
end
end
lowhigh = (ilowhigh - 1)/(nbins-1); % convert to range [0 1]
%-------------------------------------------------------
function show_busy(hfig)
ud = get(hfig,'UserData');
h = ud.h;
h_inactive = [h.img_popup h.truecolor_radio h.nir_radio h.swir_radio ...
h.custom_radio h.singleband_radio h.info h.close];
set(h_inactive,'Enable','inactive')
if (get(h.custom_radio,'Value') == 1)
h_custom = [h.red_popup h.green_popup h.blue_popup];
set(h_custom,'Enable','inactive')
elseif (get(h.singleband_radio,'Value') == 1)
set(h.intensity_popup,'Enable','inactive')
end
set(hfig,'pointer','watch')
drawnow
%-------------------------------------------------------
function show_ready(hfig)
ud = get(hfig,'UserData');
h = ud.h;
h_enable1 = [h.img_popup h.truecolor_radio h.nir_radio h.swir_radio,...
h.custom_radio h.singleband_radio h.info h.close];
set(h_enable1,'Enable','on')
% check state of radio buttons to decide what else to enable
if ( get(h.custom_radio,'Value') == 1 ) % custom
h_enable2 = [h.red_popup h.green_popup h.blue_popup];
elseif ( get(h.singleband_radio,'Value') == 1 ) % singleband
h_enable2 = h.intensity_popup;
else
h_enable2 = []; % nothing else to enable
end
set(h_enable2,'Enable','on')
set(hfig,'pointer','arrow')
drawnow
%-------------------------------------------------------
function hfig = DemoFigHandle
hfig = findobj(allchild(0),'Tag','LANdemo');
%-------------------------------------------------------
function hfig = create_gui
fig_color = [0.8 0.8 0.8];
hfig = figure('Tag','LANdemo',...
'Visible','off',...
'HandleVisibility','callback',...
'Resize','off',...
'menubar','none', ...
'Units','pixels',...
'IntegerHandle','off',...
'NumberTitle','off',...
'Name','Landsat Color Composite Demo',...
'Pointer','watch',...
'Color',fig_color,...
'DoubleBuffer','on',...
'Colormap',gray(256));
create_menus(hfig);
create_gui_elements(hfig);
position_gui_elements(hfig)
%-------------------------------------------------------
function create_menus(hfig)
% Menus
% File menu
mFile = uimenu('parent',hfig,'label','&File');
uimenu('parent',mFile,'label','&Print','callback','printdlg(gcbf);');
uimenu('parent',mFile,'label','&Close', ...
'callback','close(gcbf);','separator','on');
% Window menu
uimenu('parent',hfig, 'label','&Window', ...
'tag','winmenu', ...
'Callback', winmenu('callback'));
winmenu(hfig); % Initialize the submenu
%-------------------------------------------------------
function create_gui_elements(hfig)
text_color = [0 0 0];
status_color = [0 0 .8];
frame_color = [.45 .45 .45];
frame_label_color = [1 1 1];
radio_color = [.7 .7 .7];
fig_color = get(hfig,'color');
% image axes
h.img_axes = axes('Parent',hfig,...
'YDir','reverse',...
'XLim',[0.5 512.5],...
'YLim',[0.5 512.5],...
'CLim',[0 255],...
'XTick',[],...
'YTick',[],...
'Units','pixels');
fig_color_uint8 = uint8(round(fig_color(1)*255));
gray_img = repmat(fig_color_uint8,512,512);
h.img = image('Parent',h.img_axes,...
'CData',gray_img,...
'CDataMapping','scaled',...
'EraseMode','none');
% frame
h.frame = uicontrol('Parent',hfig, ...
'Style', 'frame', ...
'BackgroundColor', frame_color, ...
'Units', 'pixels');
% custom frame
h.custom_frame = uicontrol('Parent',hfig, ...
'Style', 'frame', ...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% singleband frame
h.singleband_frame = uicontrol('Parent',hfig, ...
'Style', 'frame', ...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% image popup label
h.img_popup_label = uicontrol('Parent',hfig,...
'Style','text',...
'String','Select an image:',...
'BackgroundColor', frame_color, ...
'ForegroundColor', frame_label_color, ...
'Units','pixels');
% image popup
% UserData tracks the value setting and is used to see if the
% selected image really changes. We set it to 0 here for
% initialization purposes.
h.img_popup = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','popupmenu',...
'String',{'Little Colorado River',...
'Mississippi River',...
'Montana',...
'Paris',...
'Rio de Janeiro',...
'Tokyo'},...
'Callback',[mfilename '(''new_image'')'],...
'UserData',0,...
'Units','pixels');
% True Color radio button
callback_str = [mfilename '(''update_radio'')'];
h.truecolor_radio = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','radiobutton',...
'String','True Color [3 2 1]',...
'UserData',1,...
'Value',1,...
'Callback',callback_str,...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% Near Infrared radio button
callback_str = [mfilename '(''update_radio'')'];
h.nir_radio = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','radiobutton',...
'String','Near Infrared [4 3 2]',...
'UserData',0,...
'Value',0,...
'Callback',callback_str,...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% Shortwave Infrared radio button
callback_str = [mfilename '(''update_radio'')'];
h.swir_radio = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','radiobutton',...
'String','Shortwave Infrared [7 4 3]',...
'UserData',0,...
'Value',0,...
'Callback',callback_str,...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% Custom Composite radio button
callback_str = [mfilename '(''update_radio'')'];
h.custom_radio = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','radiobutton',...
'String','Custom Composite',...
'UserData',0,...
'Value',0,...
'Callback',callback_str,...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
% Single Band radio button
callback_str = [mfilename '(''update_radio'')'];
h.singleband_radio = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','inactive',...
'Style','radiobutton',...
'String','Single Band Intensity',...
'UserData',0,...
'Value',0,...
'Callback',callback_str,...
'BackgroundColor', radio_color, ...
'Units', 'pixels');
band_string = {'1','2','3','4','5','6','7'};
% Red popup
h.red_popup = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','off',...
'Style','popupmenu',...
'String',band_string,...
'Callback',[mfilename '(''update_band'')'],...
'UserData',3,...
'Value',3,...
'Units','pixels');
% Green popup
h.green_popup = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','off',...
'Style','popupmenu',...
'String',band_string,...
'Callback',[mfilename '(''update_band'')'],...
'UserData',1,...
'Value',1,...
'Units','pixels');
% Blue popup
h.blue_popup = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','off',...
'Style','popupmenu',...
'String',band_string,...
'Callback',[mfilename '(''update_band'')'],...
'UserData',7,...
'Value',7,...
'Units','pixels');
% Intensity popup
h.intensity_popup = uicontrol('Parent',hfig,...
'Interruptible','off',...
'Enable','off',...
'Style','popupmenu',...
'String',band_string,...
'Callback',[mfilename '(''update_band'')'],...
'UserData',5,...
'Value',5,...
'Units','pixels');
% Red label
h.red_popup_label = uicontrol('Parent',hfig,...
'Style','text',...
'String','Red',...
'BackgroundColor', radio_color, ...
'ForegroundColor',[.8 0 0],...
'Units','pixels');
% Green label
h.green_popup_label = uicontrol('Parent',hfig,...
'Style','text',...
'String','Green',...
'BackgroundColor', radio_color, ...
'ForegroundColor',[0 .5 0],...
'Units','pixels');
% Blue label
h.blue_popup_label = uicontrol('Parent',hfig,...
'Style','text',...
'String','Blue',...
'BackgroundColor', radio_color, ...
'ForegroundColor',[0 0 .8],...
'Units','pixels');
% stretch checkbox
h.stretch = uicontrol('parent',hfig, ...
'Style','checkbox',...
'String','Saturation Stretch', ...
'Callback', [mfilename '(''display_image'')'],...
'Value',1,...
'Units','pixels');
% Info button
h.info = uicontrol('Parent',hfig, ...
'Interruptible','off',...
'Enable', 'inactive', ...
'Style', 'pushbutton', ...
'String', 'Info', ...
'Callback', 'helpwin(''landsatdemo'')', ...
'Units', 'pixels');
% Close button
h.close = uicontrol('Parent',hfig, ...
'Interruptible','off',...
'Enable', 'inactive', ...
'Style', 'pushbutton', ...
'String', 'Close', ...
'Callback', 'delete(gcbf)', ...
'Units', 'pixels');
ud.h = h;
set(hfig,'UserData',ud); % Store handles of gui elements in figure userdata
%-------------------------------------------------------
function position_gui_elements(hfig)
ud = get(hfig,'UserData');
h = ud.h;
geom = imuigeom; %imuigeom is a private function to set location of gui elements
gutter = 20; % pixels
image_width = 512;
image_height = 512;
label_gap = 5;
bottom = gutter;
top = bottom + image_height + gutter; % top of figure
left1 = gutter;
% find position of h.img
pos.img_axes = [left1 bottom image_width image_height];
left2 = pos.img_axes(1) + image_width + gutter + label_gap;
% image popup label
extent.img_popup_label = find_extent(h.img_popup_label,geom.text);
bottom1 = top - gutter - label_gap - extent.img_popup_label(4);
pos.img_popup_label = [left2 bottom1 extent.img_popup_label(3:4)];
% image popup
extent.img_popup = find_popup_extent(h.img_popup,geom.popupmenu);
bottom2 = bottom1 - extent.img_popup(4);
pos.img_popup = [left2 bottom2 extent.img_popup(3:4)];
% find extent of widest radio button
extent.radio = find_extent(h.swir_radio,geom.radiobutton);
width_radio = extent.radio(3);
height_radio = extent.radio(4);
bottom3 = bottom2 - 5*label_gap - height_radio;
bottom4 = bottom3 - label_gap - height_radio;
bottom5 = bottom4 - label_gap - height_radio;
bottom6 = bottom5 - label_gap - height_radio;
pos.truecolor_radio = [left2 bottom3 extent.radio(3:4)];
pos.nir_radio = [left2 bottom4 extent.radio(3:4)];
pos.swir_radio = [left2 bottom5 extent.radio(3:4)];
pos.custom_radio = [left2 bottom6 extent.radio(3:4)];
% band popups
extent.band_popup = find_extent(h.red_popup,geom.popupmenu);
width_band_popup = extent.band_popup(3);
height_band_popup = extent.band_popup(4);
left_red = left2 + 4*label_gap;
left_green = left_red + width_band_popup + 2*label_gap;
left_blue = left_green + width_band_popup + 2*label_gap;
bottom7 = bottom6 - label_gap - height_band_popup;
pos.red_popup = [left_red bottom7 extent.band_popup(3:4)];
pos.green_popup = [left_green bottom7 extent.band_popup(3:4)];
pos.blue_popup = [left_blue bottom7 extent.band_popup(3:4)];
% band labels
extent.band_popup_label = find_extent(h.green_popup_label,geom.text);
bottom8 = bottom7 - label_gap - extent.band_popup_label(4);
pos.red_popup_label = [left_red bottom8 extent.band_popup_label(3:4)];
pos.green_popup_label = [left_green bottom8 extent.band_popup_label(3:4)];
pos.blue_popup_label = [left_blue bottom8 extent.band_popup_label(3:4)];
% custom frame
bottom9 = bottom8 - label_gap;
height_custom_frame = bottom6 + height_radio - bottom9 + 1;
pos.custom_frame = [left2-1 bottom9 width_radio+2 height_custom_frame];
% Single Band radio button and popup
bottom10 = bottom9 - 2*label_gap - height_radio;
pos.singleband_radio = [left2 bottom10 extent.radio(3:4)];
bottom11 = bottom10 - label_gap - height_band_popup;
pos.intensity_popup = [left_green bottom11 extent.band_popup(3:4)];
% single band frame
bottom12 = bottom11 - label_gap;
height_singleband_frame = bottom10 + height_radio - bottom12 + 1;
pos.singleband_frame=[left2-1 bottom12 width_radio+2 height_singleband_frame];
% stretch checkbox
bottom13 = bottom12 - 10*label_gap - height_radio;
pos.stretch = [left2 bottom13 width_radio height_radio];
% close button
bottom15 = bottom + label_gap;
extent.button = find_extent(h.close,geom.pushbutton);
height_button = extent.button(4);
pos.close = [left2 bottom15 width_radio height_button];
% info button
bottom14 = bottom15 + height_button + label_gap;
pos.info = [left2 bottom14 width_radio height_button];
% find figure size
max_width = max([extent.img_popup(3) width_radio]);
frame_width = max_width + 2*label_gap;
pos.frame = [left2-label_gap bottom frame_width image_height];
figureWidth = left2 + max_width + gutter + label_gap;
figureHeight = top;
%
% Adjust figure position - copied from qtdemo
%
horizDecorations = 30; % resize controls, etc.
vertDecorations = 65; % title bar, etc.
screenSize = get(0,'ScreenSize');
if (screenSize(3) <= 1)
% No display connected (apparently)
screenSize(3:4) = [100000 100000]; % don't use Inf because of vms
end
if (((figureWidth + horizDecorations) > screenSize(3)) | ...
((figureHeight + vertDecorations) > screenSize(4)))
% Screen size is too small for this demo!
delete(hfig);
error(['Screen resolution is too low ', ...
'(or text fonts are too big) to run this demo']);
end
figPos = get(hfig, 'Position');
figPos(3:4) = [figureWidth figureHeight];
dx = screenSize(3) - figPos(1) - figPos(3) - horizDecorations;
dy = screenSize(4) - figPos(2) - figPos(4) - vertDecorations;
if (dx < 0)
figPos(1) = figPos(1) + dx;
end
if (dy < 0)
figPos(2) = figPos(2) + dy;
end
set(hfig, 'Position', figPos)
set(h.img_axes,'Position',pos.img_axes)
set(h.frame,'Position',pos.frame)
set(h.img_popup_label,'Position',pos.img_popup_label)
set(h.img_popup,'Position',pos.img_popup)
set(h.truecolor_radio,'Position',pos.truecolor_radio)
set(h.nir_radio,'Position',pos.nir_radio)
set(h.swir_radio,'Position',pos.swir_radio)
set(h.custom_frame,'Position',pos.custom_frame)
set(h.custom_radio,'Position',pos.custom_radio)
set(h.red_popup,'Position',pos.red_popup)
set(h.green_popup,'Position',pos.green_popup)
set(h.blue_popup,'Position',pos.blue_popup)
set(h.red_popup_label,'Position',pos.red_popup_label)
set(h.green_popup_label,'Position',pos.green_popup_label)
set(h.blue_popup_label,'Position',pos.blue_popup_label)
set(h.singleband_frame,'Position',pos.singleband_frame)
set(h.singleband_radio,'Position',pos.singleband_radio)
set(h.intensity_popup,'Position',pos.intensity_popup)
set(h.stretch,'Position',pos.stretch)
set(h.info,'Position',pos.info)
set(h.close,'Position',pos.close)
%-------------------------------------------------------
function extent = find_extent(h,fudge_factor)
extent = get(h, 'Extent');
extent = extent + fudge_factor;
%-------------------------------------------------------
function extent = find_popup_extent(h,fudge_factor)
popup_string = get(h,'string');
max_length = 0; % find longest string of popup
for i = 1:length(popup_string)
i_length = length(popup_string{i});
if ( i_length > max_length )
max_length = i_length;
i_longest = i;
end
end
dummy = popup_string{i_longest};
set(h,'string',dummy);
extent = get(h, 'Extent'); % use longest string to get extent
set(h,'string',popup_string); % restore actual string
extent = extent + fudge_factor;