imtile

Combine multiple image frames into one rectangular tiled image

Syntax

out = imtile(filenames)

out = imtile(I)

out = imtile(images)

out = imtile(imds)

out = imtile(___,map)

out = imtile(___,Name=Value)

Description

out = imtile(filenames) returns a tiled image containing the images in the files with file names filenames.

By default, the imtile function arranges the images so that they roughly form a square. You can change the arrangement using optional name-value arguments. The images can have different sizes and data types.

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

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

out = imtile(I) returns a tiled image containing all the frames of the multiframe image array I. A multiframe image array can be a sequence of binary, grayscale, or truecolor images.

out = imtile(images) returns a tiled image containing the images specified in the cell array images. imtile displays empty cell array elements as a blank tile.

out = imtile(imds) returns a tiled image containing the images specified in the image datastore imds. For information about image datastores, see ImageDatastore.

out = imtile(___,map) returns a tiled image in which grayscale, indexed, and binary images are converted to RGB using the colormap map. You can specify input images using the input argument of any of the preceding syntaxes. Note that if you specify images using file names filenames, and also specify the colormap, then map overrides any internal colormap present in the image files.

out = imtile(___,Name=Value) returns a customized tiled image, depending on the values of the optional name-value arguments.

Examples

Create Tiled Image from Files

Specify two image files, then create a tiled image containing the images.

files = ["peppers.png","ngc6543a.jpg"];
out = imtile(files);

Display the tiled image.

imshow(out)

Customize Number of Images in Tiled Image

Load the MRI data set that contains a volumetric image and a colormap.

load mri

Create a tiled image from all slices in the image volume.

out = imtile(D,map);
imshow(out)

Create a tiled image containing only the first eight images in the data set. Arrange the images in a 2-by-4 grid by using the GridSize name-value argument.

out = imtile(D,map,Frames=1:8,GridSize=[2 4]);
imshow(out)

Inspect Color Planes of RGB Image

Read an RGB image into the workspace.

imRGB = imread('peppers.png');

Create a tiled image containing each of the three planes of the RGB image. Display the tiled image.

out = imtile(imRGB);
imshow(out)

Create Tiled Image from Image Datastore

From an image datastore, create and customize a tiled image.

Create an image datastore containing all the files with the file extension "tif" or "png" in the specified folder.

fileFolder = fullfile(matlabroot,"toolbox","matlab","matlab_images");
imds = imageDatastore(fileFolder,IncludeSubfolders=true, ...
    FileExtensions=[".tif",".png"]);

Create a tiled image containing the images in the datastore.

out1 = imtile(imds);
imshow(out1)

Add a blue border to the tiled image by using the BorderSize and BackgroundColor name-value arguments.

out2 = imtile(imds,BorderSize=10,BackgroundColor="b");
figure
imshow(out2)

Input Arguments

filenames — Names of files containing images

f-by-1 string array | 1-by-f string array | character vector | cell array of character vectors

Names of files containing images, specified as an f-by-1 string array, a 1-by-f string array, a character vector, or a cell array of character vectors. 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.

Example: 'file1.jpg'

Example: ["file1.jpg" "file2.jpg"]

Example: '../dir/data/file1.png'

Example: {'C:\dir\data\file1.tif','C:\dir\data\file2.tif'}

Data Types: char | string | cell

I — Multiframe image

numeric array

Multiframe image, specified as a numeric array. I can be:

• An m-by-n-by-k array representing a sequence of k binary, grayscale, or indexed images

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

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

images — List of images

k-by-1 cell array | 1-by-k cell array

List of images, specified as an k-by-1 or 1-by-k cell array of numeric matrices. The cell array can contain numeric matrices of size m-by-n or m-by-n-by-3.

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 of map is a three-element RGB triplet that specifies the red, green, and blue components of a single color. When you specify map, the imtile function converts all indexed, grayscale, and binary images to truecolor using this colormap.

Data Types: double

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: imtile("peppers.png",BackgroundColor="g"); specifies a green background color.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: imtile("peppers.png","BackgroundColor","g");

BackgroundColor — Color of background

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

Color of the background, specified as an RGB triplet, a color name, or a short color name. The imtile function fills all blank spaces with this color, including the space specified by BorderSize.

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]

Example: "BackgroundColor","r"

Example: "BackgroundColor","green"

Example: "BackgroundColor",[0 0.4470 0.7410]

BorderSize — Padding around each thumbnail image

[0 0] (default) | numeric scalar | 1-by-2 numeric vector

Padding around each thumbnail image, specified as a numeric scalar or 1-by-2 numeric vector of the form [brows bcols]. The imtile function pads the borders of each image with the background color.

Frames — Frames to include

total number of images (default) | numeric array | logical mask

Frames to include, specified as a numeric array or a logical mask. The imtile function interprets the values as indices into the image array or cell array. The following examples create a tiled image containing the first three image frames.

Example: out = imtile(I,Frames=1:3);

Example: out = imtile(I,Frames=[true true true]);

GridSize — Number of rows and columns of thumbnails

two-element vector

Number of rows and columns of thumbnails in the tiled image, specified as a two-element vector of the form [nrows ncols]. nrows specifies the number of rows in the grid and ncols specifies the number of columns in the grid. Use NaNs or Infs to have imtile calculate the size in a particular dimension in a way that includes all the images.

• If GridSize is [2 NaN], then imtile creates a tiled image with two rows and the number of columns necessary to include all the images.

• If both the elements are NaN or Inf, then imtile calculates the grid size to form a square. imtile returns the images horizontally across columns.

• If there is a mismatch between GridSize and number of images (frames), then imtile creates the tiled image based on GridSize.

ThumbnailInterpolation — Interpolation method to resize images for thumbnails

"bicubic" (default) | "bilinear" | "nearest" | ...

Interpolation method to resize images for thumbnails, specified as one of these values.

Method	Description
"bicubic"	Bicubic interpolation; the output pixel value is a weighted average of pixels in the nearest 4-by-4 neighborhood. Note Bicubic interpolation can produce pixel values outside the original range.
"bilinear"	Bilinear interpolation; the output pixel value is a weighted average of pixels in the nearest 2-by-2 neighborhood.
"nearest"	Nearest-neighbor interpolation; the output pixel is assigned the value of the pixel that the point falls within. No other pixels are considered.
"box"	Box-shaped interpolation kernel
"triangle"	Triangular interpolation kernel (equivalent to "bilinear")
"cubic"	Cubic interpolation kernel (equivalent to "bicubic")
"lanczos2"	Lanczos-2 interpolation kernel
"lanczos3"	Lanczos-3 interpolation kernel

The default resizing method, "bicubic", typically works well when the images are larger than the thumbnails. If the size of your images is smaller than the thumbnails and you want to avoid smoothing the pixel values, then consider setting ThumbnailInterpolation as "nearest".

Data Types: char | string

ThumbnailSize — Size of thumbnails

full size of first image (default) | two-element vector

Size of thumbnails, specified as a two-element vector of the form [trows tcols], in pixels. The imtile function preserves the aspect ratio of the original image by zero-padding the boundary.

• If you specify a NaN or Inf, then the imtile function calculates the corresponding value automatically to preserve the aspect ratio of the first image.

• If you specify an empty array ([]), then the imtile function uses the full size of the first image as the thumbnail size.

Output Arguments

out — Tiled output image

numeric matrix | numeric array

Tiled output image, returned as a numeric matrix or a numeric array. The output image is an M-by-N-by-3 numeric array when any of these conditions are true:

• At least one of the input images is an RGB image or indexed image

• You specify a colormap, map

• You specify a background color, BackgroundColor, regardless of whether the tiled image includes background pixels or not

Extended Capabilities

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced in R2018b

R2024b: Control method to resize images for thumbnails

The new ThumbnailInterpolation name-value argument enables you to specify the interpolation method used to resize images for thumbnails.