montage

Display multiple image frames as rectangular montage

Syntax

montage(I)

montage(imagelist)

montage(filenames)

montage(imds)

montage(___,map)

montage(___,Name,Value)

img = montage(___)

Description

montage(I) displays all frames of a multiframe image array I. By default, the montage function arranges the images so that they roughly form a square.

montage(imagelist) displays a montage of images specified in the cell array imagelist. The images can be of different types and sizes.

montage(filenames) displays a montage of the images with file names specified in filenames.

montage(imds) displays a montage of the images specified in the image datastore imds.

montage(___,map) treats all grayscale and binary images (specified using any of the preceding syntaxes) as indexed images and displays them with the specified colormap map. If you specify images using file names or an image datastore, then map overrides any internal colormap present in the image files. montage does not modify the colormap of RGB images.

montage(___,Name,Value) uses name-value pair arguments to customize the display of the image montage.

img = montage(___) returns a handle to the single image object that contains all the frames displayed.

Examples

Create Montage from Multiframe Image

Create an m-by-n-by-4 multiframe image from a series of grayscale images. The images must all be the same size.

img1 = imread('AT3_1m4_01.tif');
img2 = imread('AT3_1m4_02.tif');
img3 = imread('AT3_1m4_03.tif');
img4 = imread('AT3_1m4_04.tif');
multi = cat(3,img1,img2,img3,img4);

Display a montage of the images in the multiframe image.

montage(multi);

Create Montage Containing Images of Different Types and Sizes

Read several images of different types and sizes into the workspace.

imRGB = imread('peppers.png');
imGray = imread('coins.png');

Display a montage containing all of the images.

figure
montage({imRGB, imGray, 'cameraman.tif'})

Create Montage from Images in Files

Create a montage from a series of images in files. Make the montage a 2-by-5 rectangle. Then, create a second montage, this time using the 'DisplayRange' name-value argument to highlight structures in the image.

Display the Images as a Rectangular Montage

Create a string array containing a series of file names.

fileFolder = fullfile(matlabroot,'toolbox','images','imdata');
dirOutput = dir(fullfile(fileFolder,'AT3_1m4_*.tif'));
fileNames = string({dirOutput.name});

Display the images as a montage. Specify the shape of the montage as a 2-by-5 rectangle.

montage(fileNames,'Size',[2 5]);

Adjust the Contrast of the Images in the Montage

In another figure, create the same 2-by-5 montage. In addition, specify the display range to adjust the contrast of the images in the montage.

figure 
montage(fileNames,'Size',[2 5],'DisplayRange',[75 200]);

Customize Number of Images in Montage

View all the images in a MRI data set using montage with default settings. There are 27 images in the set.

load mri
montage(D, map)

Create a new montage containing only the first 9 images.

figure
montage(D, map, 'Indices', 1:9);

Create Montage from Image Datastore

Create an ImageDatastore object containing a series of ten images from the Image Processing Toolbox™ sample image folder.

fileFolder = fullfile(matlabroot,'toolbox','images','imdata');
imds = imageDatastore(fullfile(fileFolder,'AT3*'));

Display the contents of the datastore as a montage.

montage(imds)

Input Arguments

I — Multiframe image array

numeric array

Multiframe image array, specified as one of the following:

• m-by-n-by-k numeric array representing a sequence of k binary or grayscale images

• m-by-n-by-1-by-k numeric array representing a sequence of k binary or grayscale images

• m-by-n-by-3-by-k numeric array representing a sequence of k truecolor images

Data Types: single | double | int16 | uint8 | uint16 | logical

imagelist — Set of images

cell array of numeric matrices

Set of images, specified as a cell array of numeric matrices of size m-by-n or m-by-n-by-3.

Data Types: single | double | int16 | uint8 | uint16 | logical | cell

filenames — Names of files containing images

cell array of character vectors | vector of strings

Names of files containing image, specified as a cell array of character vectors or a vector of strings. If the files are not in the current folder or in a folder on the MATLAB^® path, then specify the full path name. For more information, see imread.

Data Types: char | string | cell

imds — Image datastore

ImageDatastore object

Image datastore, specified as an ImageDatastore object.

map — Colormap

c-by-3 numeric matrix

Colormap, specified as a c-by-3 numeric matrix with values in the range [0, 1]. Each row is a three-element RGB triplet that specifies the red, green, and blue components of a single color of the colormap.

Data Types: double

Name-Value Arguments

Specify optional comma-separated pairs of Name,Value arguments. Name is the argument name and Value is the corresponding value. Name must appear inside quotes. You can specify several name and value pair arguments in any order as Name1,Value1,...,NameN,ValueN.

Example: 'Indices',1:9 creates a montage of the first nine frames

BackgroundColor — Background color

'black' (default) | RGB triplet | color name | short color name

Background color, specified as specified as an RGB triplet, a color name, or a short color name. The montage function fills all blank spaces with the background color, including the space specified by BorderSize. If you specify a background color, then the montage function renders the output as an RGB image.

You can specify any color using an RGB triplet. An RGB triplet is a 3-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1].

You can specify some common colors by name as a string scalar or character vector. This table lists the named color options and the equivalent RGB triplets.

Color Name	Short Name	RGB Triplet	Appearance
'red'	'r'	[1 0 0]
'green'	'g'	[0 1 0]
'blue'	'b'	[0 0 1]
'cyan'	'c'	[0 1 1]
'magenta'	'm'	[1 0 1]
'yellow'	'y'	[1 1 0]
'black'	'k'	[0 0 0]
'white'	'w'	[1 1 1]

Here are the RGB triplets for the default colors that MATLAB uses in many types of plots.

RGB Triplet	Appearance
[0 0.4470 0.7410]
[0.8500 0.3250 0.0980]
[0.9290 0.6940 0.1250]
[0.4940 0.1840 0.5560]
[0.4660 0.6740 0.1880]
[0.3010 0.7450 0.9330]
[0.6350 0.0780 0.1840]

Example: 'BackgroundColor','r'

Example: 'BackgroundColor','green'

Example: 'BackgroundColor',[0 0.4470 0.7410]

BorderSize — Padding around each thumbnail image

[0 0] (default) | nonnegative integer | 1-by-2 vector of nonnegative integers

Padding around each thumbnail image, in pixels, specified as a nonnegative integer or a 1-by-2 vector of nonnegative integers. The montage function pads the image borders with the background color, BackgroundColor.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

DisplayRange — Display range

1-by-2 vector

Display range of grayscale images in array I, specified as 1-by-2 vector of the form [low high]. All pixel values less than or equal to low display as black. All pixel values greater than or equal to high display as white. If you specify an empty matrix ([]), then montage uses the minimum and maximum pixel values of the images.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Indices — Frames to display

array of positive integers

Frames to display in the montage, specified as an array of positive integers. The montage function interprets the values as indices into array I or into cell array filenames or imagelist.

By default, the montage function displays all frames or image files.

Example: 'Indices',1:4 create a montage of the first four frames in I

Example: 'Indices',1:2:20 displays every other frame.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Interpolation — Interpolation technique

'nearest' (default) | 'bilinear'

Interpolation technique used when scaling an image, specified as the comma-separated pair consisting of 'Interpolation' and one of these values.

Value	Description
'nearest'	Nearest neighbor interpolation (default)
'bilinear'	Bilinear interpolation

Parent — Parent of image object

axes object

Parent of the image object created by montage, specified as an axes object. The montage function resizes the image to fit the extents available in the parent axes.

Size — Number of rows and columns of images

2-element vector

Number of rows and columns of images, specified as a 2-element vector of the form [nrows ncols].

If you specify NaN or Inf for a particular dimension, then the montage function calculates the value of the dimension to display all images in the montage. For example, if 'Size' is [2 NaN], then the montage will have two rows and the minimum number of columns to display all images. When there is a mismatch between 'Size' and number of images (frames) specified, then the montage function creates the tiled image based on 'Size'.

Data Types: single | double

ThumbnailSize — Size of each thumbnail

2-element vector of positive integers | []

Size of each thumbnail, in pixels, specified as a 2-element vector of positive integers. The aspect ratio of each image is preserved, and any blank space is filled with the background color, BackgroundColor.

If you specify an empty array ([]), then the thumbnail size is the full size of the first image. If you specify either element as NaN or Inf, then the montage function calculates the corresponding value automatically to preserve the aspect ratio of the first image.

Data Types: single | double

Output Arguments

img — Montage image

Image object

Montage image, returned as an Image object.

Tips

• If you specify an indexed image, then montage converts it to RGB using the colormap present in the file.

• If there is a data type mismatch between images, then the montage function converts all images to data type double using the im2double function.

• When calculating the number of images to display horizontally and vertically, montage considers the aspect ratio of the images, so that the displayed montage is nearly square.