List of builtin demo images

Where can one find a list of MATLAB's pre-packaged demo images, like 'camerman', 'coins', etc...?

[Matt Fig]

I've wondered that myself....

[Star Strider]

I found the list in my installation in the directory and file:

C:\Program Files\MATLAB\R2012b\toolbox\images\imdemos\Contents.m

[Andreas Goser]

Looks like I am bit late in that discussion, but I wonder WHY is that important to know?

[Image Analyst]

Sometimes you want to demonstrate a concept to a questioner and they did not supply an image, or you want to use a standard image so that everyone can try your demo code instead of just the original poster.

[praks]

C:\Program Files\matlab\toolbox\images\imdemos

[Image Analyst]

praks, that used to be true until R2014a, when they moved the demo images from the imdemos folder to the imdata folder. The robust way to get the folder where the demo images are located is to use my code:

% Prior to R2014a, demo images were in
% C:\Program Files\MATLAB\R2013b\toolbox\images\imdemos
% Starting with R2014a, demo images are now located in
% C:\Program Files\MATLAB\R2014a\toolbox\images\imdata
structVersion = ver; % Get version information.
if strcmp(structVersion(1).Release, '(R2014a)')
  folder = fullfile(matlabroot, '\toolbox\images\imdata');
else
  folder = fullfile(matlabroot, '\toolbox\images\imdemos');
end
if exist(folder, 'dir')
  fprintf('Demo Images Folder is %s.\n', folder);
else
  fprintf('Folder %s does not exist.\n', folder);
end

Of course, you can get rid of the comments and fprintf statements when you transfer it to your code if you want.

[Matt J]

I think my proposal here is even more robust. It should work no matter where they move the image files, assuming they keep them all together in the same directory, of course. Admittedly, though, I haven't yet tried it in R2014.

Answer 1

[Matt Fig]

UPDATED To printe 2 columns instead of one. Even better for my command window (but not for this forum) is to print 3 columns.

I ran this and the output is shown below (did I miss something?):

wd = pwd;
cd('C:\Program Files\MATLAB\R2011b\toolbox\images\imdemos')
D = dir;
cd(wd)
C = {'.tif';'.jp';'.png';'.bmp'};
idx = false(size(D));

for ii = 1:length(C)
    idx = idx | (arrayfun(@(x) any(strfind(x.name,C{ii})),D));
end

D = D(idx);
L = length(D);

for ii = 1:2:numel(D)
    fprintf('%25s %25s\n',D(ii:min(ii+1,L)).name)
end

fprintf('\n')

           AT3_1m4_01.tif            AT3_1m4_02.tif
           AT3_1m4_03.tif            AT3_1m4_04.tif
           AT3_1m4_05.tif            AT3_1m4_06.tif
           AT3_1m4_07.tif            AT3_1m4_08.tif
           AT3_1m4_09.tif            AT3_1m4_10.tif
               autumn.tif                   bag.png
                blobs.png                 board.tif
            cameraman.tif                 canoe.tif
                 cell.tif                circbw.tif
              circles.png               circuit.tif
                coins.png         concordaerial.png
    concordorthophoto.png                 eight.tif
               fabric.png              football.jpg
               forest.tif           gantrycrane.png
                glass.png                greens.jpg
              hestain.png                  kids.tif
          liftingbody.png                  logo.tif
                  m83.tif                 mandi.tif
                 moon.tif                   mri.tif
             office_1.jpg              office_2.jpg
             office_3.jpg              office_4.jpg
             office_5.jpg              office_6.jpg
                onion.png                paper1.tif
                pears.png               peppers.png
             pillsetc.png                  pout.tif
                 rice.png                saturn.png
               shadow.tif            snowflakes.png
                spine.tif                  tape.png
             testpat1.png                  text.png
                 tire.tif                tissue.png
                trees.tif     westconcordaerial.png
westconcordorthophoto.png

[Matt J]

Thanks. I tweaked it as follows to make it a bit more platform/version independent.

function varargout=demoimgs

    pth = fileparts(which('cameraman.tif'));

    D = dir(pth);

    C = {'.tif';'.jp';'.png';'.bmp'};
    idx = false(size(D));
    for ii = 1:length(C)
        idx = idx | (arrayfun(@(x) any(strfind(x.name,C{ii})),D));
    end
    D = D(idx);
    for ii = 1:numel(D)
        fprintf('%s\n',D(ii).name)
    end

    if nargout, varargout{1}=pth; end

[Matt Fig]

Cool!

[Star Strider]

There are actually 140 image files in various formats in that directory, including .dcm and others. That's the reason I suggested the ‘Contents.m’ file.

[Nour]

what about RGB? only 'peppers.jpg'?

[DGM]

Those are just the images in the IPT imdata/ directory. There are also a couple images in the base toolbox, specifically, peppers.png

which cameraman.tif -all % in IPT

/MATLAB/toolbox/images/imdata/cameraman.tif

which peppers.png -all % in base

/MATLAB/toolbox/matlab/imagesci/peppers.png
/MATLAB/examples/deeplearning_shared/data/peppers.png  % Shadowed
/MATLAB/examples/rptgen/data/peppers.png               % Shadowed

% what else is in imagesci/? not much.
pth = fileparts(which('peppers.png'));
D = dir(pth);
C = {'.tif';'.jp';'.png';'.bmp'};
idx = false(size(D));
for ii = 1:length(C)
    idx = idx | (arrayfun(@(x) any(strfind(x.name,C{ii})),D));
end
D = D(idx);
for ii = 1:numel(D)
    fprintf('%s\n',D(ii).name)
end

corn.tif
peppers.png

Answer 2

[Adam Danz]

Update: Starting in Matlab R2021b, the documentation contains a list of some built-in images and their descriptions in Matlab Example Data sets.

-------------------------------------------------------------

Using the wisdom shared within the two pre-existing answers to this question, I've developed a function that finds all image files in a directory and plots their thumbnails along with numeric lables. A table is printed to the command window defining the image name for each numeric label. When the function is run without inputs, it searches for files in the \toolbox\images\imdata directory (r2021a).

showImageThumbnails() - available on the file exchange

Sample of output:

Images in directory C:\Program Files\MATLAB\R2021a\toolbox\images\imdata

Ref num. Name Size (KB)

________ _________________________ _________

1 AT3_1m4_01.tif 310.2

2 AT3_1m4_02.tif 310.43

3 AT3_1m4_03.tif 310.31

4 AT3_1m4_04.tif 310.34

5 AT3_1m4_05.tif 310.38

6 AT3_1m4_06.tif 310.34

7 AT3_1m4_07.tif 310.35

8 AT3_1m4_08.tif 310.36

9 AT3_1m4_09.tif 310.27

10 AT3_1m4_10.tif 310.29

11 DistortedImage.png 426.38

12 autumn.tif 214.11

13 baby.jpg 826

14 bag.png 35.582

15 blobs.png 1.094

16 board.tif 573.54

17 cameraman.tif 65.24

18 canoe.tif 71.548

19 car1.jpg 4950.5

20 car2.jpg 4057.4

21 car_1.jpg 45.785

22 car_2.jpg 25.374

23 car_3.jpg 20.081

24 car_4.jpg 7.254

25 cell.tif 31.028

26 circbw.tif 4.122

27 circles.png 0.917

28 circlesBrightDark.png 8.227

29 circuit.tif 76.77

30 coins.png 37.906

31 colorCheckerTestImage.jpg 158.32

32 coloredChips.png 303.78

33 concordorthophoto.png 4685.3

34 eSFRTestImage.jpg 3253.3

35 eight.tif 59.64

36 fabric.png 626.53

37 flamingos.jpg 220.56

38 foggyroad.jpg 341.89

39 foggysf1.jpg 1524.8

40 foggysf2.jpg 565.88

41 foosball.jpg 3200.5

42 football.jpg 27.13

43 forest.tif 128.81

44 gantrycrane.png 133.63

45 glass.png 20.908

46 greens.jpg 74.948

47 hallway.jpg 3135.3

48 hands1-mask.png 1.193

49 hands1.jpg 22.157

50 hands2.jpg 22.133

51 hestain.png 131.63

52 hotcoffee.tif 307.4

53 indiancorn.jpg 209.82

54 kids.tif 97.058

55 kobi.png 2446.8

56 liftingbody.png 125.39

57 lighthouse.png 484.36

58 llama.jpg 135.47

59 logo.tif 1.31

60 lowlight_1.jpg 81.035

61 lowlight_2.jpg 181.56

62 m83.tif 150.39

63 mandi.tif 6100.7

64 micromarket.jpg 4174.8

65 moon.tif 184.39

66 mri.tif 232.37

67 office_1.jpg 60.155

68 office_2.jpg 95.705

69 office_3.jpg 127.73

70 office_4.jpg 141.99

71 office_5.jpg 146.64

72 office_6.jpg 126.53

73 onion.png 44.638

74 paper1.tif 49.458

75 parkavenue.jpg 422.96

76 peacock.jpg 317.1

77 pears.png 554.55

78 pillsetc.png 397.45

79 pout.tif 69.296

80 printedtext.png 583.91

81 rice.png 44.607

82 riceblurred.png 34.526

83 saturn.png 1166.1

84 sevilla.jpg 435.38

85 shadow.tif 70.02

86 sherlock.jpg 47.172

87 snowflakes.png 20.48

88 spine.tif 73.166

89 strawberries.jpg 171.44

90 tape.png 284.4

91 testpat1.png 16.268

92 text.png 1.322

93 threads.png 63.106

94 tire.tif 47.962

95 tissue.png 1037

96 toyobjects.png 2.429

97 toysflash.png 1035.5

98 toysnoflash.png 1133.8

99 trailer.jpg 144.85

100 trees.tif 1778.9

101 wagon.jpg 184.49

102 westconcordaerial.png 298.8

103 westconcordorthophoto.png 104.64

104 yellowlily-segmented.png 21.292

105 yellowlily.jpg 672.46

[Image Analyst]

Nice. If the user wants to pick from a listbox, here is some code:

%===============================================================================
% Get the name of the demo image the user wants to use.
% Let's let the user select from a list of all the demo images that ship with the Image Processing Toolbox.
folder = fileparts(which('cameraman.tif')); % Determine where demo folder is (works with all versions).
% Demo images have extensions of TIF, PNG, and JPG.  Get a list of all of them.
imageFiles = [dir(fullfile(folder,'*.TIF')); dir(fullfile(folder,'*.PNG')); dir(fullfile(folder,'*.jpg'))];
baseFileNames = {imageFiles.name}';
% Sort the base file names alphabetically.
[baseFileNames, sortOrder] = sort(baseFileNames);
imageFiles = imageFiles(sortOrder);
selection = listdlg('ListString', baseFileNames, 'PromptString', 'Use which demo image?'); % Display all image file names in a popup menu.
% button = menu('Use which gray scale demo image?', ca); % Display all image file names in a popup menu.
% Get the base filename.
baseFileName = imageFiles(selection).name; % Assign the one on the button that they clicked on.
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);

[Adam Danz]

That'll be useful.

[Walter Roberson]

On MacOS, none of the example image file extensions are lowercase, at least not in that directory. But filenames are potentially case sensitive on Mac (depending on user configuration) so TIF and PNG might possibly not match anything.

[Adam Danz]

Thanks for the heads up, WR. The showImageThumbnails function ignores case when matching file extension strings. Both the file names and file extensions are forced to lower case before matching.

Answer 3

[Image Analyst]

They're in C:\Program Files\MATLAB\R2012b\toolbox\images\imdemos.

[Matt J]

Are we sure they're all in that 1 single directory?

[Matt Fig]

There are other demo images in the wavelet and mapping toolboxes, for instance.

[Image Analyst]

Yeah, they can be scattered about. For example there are some more IPT demo images in C:\Program Files\MATLAB\R2012b\toolbox\images\imdemos\html. Some of the images are the same as the other folder, but some are different. I don't know what the rationale is for what images go where. Plus the images are mixed up with m-files, etc. I've let them know that it would be cleaner if they just kept all their images in a folder called C:\Program Files\MATLAB\R2012b\toolbox\images\DemoImages, but they don't seem to want to do that for some reason.

[Image Analyst]

This used to be true until R2014a, when they moved the demo images from the imdemos folder to the imdata folder. The robust way to get the folder where the demo images are located is to use my code:

% Prior to R2014a, demo images were in
% C:\Program Files\MATLAB\R2013b\toolbox\images\imdemos
% Starting with R2014a, demo images are now located in
% C:\Program Files\MATLAB\R2014a\toolbox\images\imdata
structVersion = ver; % Get version information.
if strcmp(structVersion(1).Release, '(R2014a)')
  folder = fullfile(matlabroot, '\toolbox\images\imdata');
else
  folder = fullfile(matlabroot, '\toolbox\images\imdemos');
end
if exist(folder, 'dir')
  fprintf('Demo Images Folder is %s.\n', folder);
else
  fprintf('Folder %s does not exist.\n', folder);
end

Of course, you can get rid of the comments and fprintf statements when you transfer it to your code if you want.

[Matt J]

I think my proposal here is even more robust. It should work no matter where they move the image files, assuming they keep them all together in the same directory, of course. Admittedly, though, I haven't yet tried it in R2014.

[Image Analyst]

Yes, that is more robust. I like how you use which() to find where it lives on the search path. The only way to make it more robust would be to search the entire computer for the file if it's not found (but that would be very slow), or to check for two images in case they ever decided to get rid of cameraman. But those situations are not likely. I'd probably change it to return the folder alone and not the entire list of images in the folder - actually you could make it very general and return both.