imerase

Remove image pixels within rectangular region of interest

Syntax

Ierased = imerase(I,rect)

Ierased = imerase(I,rect,'FillValues',fillValues)

Description

Ierased = imerase(I,rect) remove pixels of image I within the rectangular region defined by rect and returns the image with the erased region, Ierased.

Ierased = imerase(I,rect,'FillValues',fillValues) also specifies the fill value to apply to the erased pixels.

Examples

Erase Pixels from Random Window

Read and display an image.

I = imread("peppers.png");
imshow(I)

Select a rectangular region of size 50-by-100 pixels from a random location in the image.

rect = randomWindow2d(size(I),[50 100]);

Erase the pixels from within the rectangular region.

J = imerase(I,rect);

Display the erased image. The erased pixels have the value 0.

imshow(J)

Erase Pixels from Specified Window

Read and display an image.

I = imread("car1.jpg");
imshow(I)

Specify the size and position of the erase rectangle as a 4-element vector of the form [xmin ymin width height].

rect = [1040 1525 250 200];

Erase the pixels from within the rectangular region, and fill the erased pixels with the color green.

J = imerase(I,rect,"FillValues",[0 255 0]);

Display the erased image.

imshow(J)

Fill Erased Region with Random Colors

Read and display a color image.

I = imread('flamingos.jpg');
imshow(I)

Select a random square window from the image. The area of the window is between 2% and 13% of the area of the entire image.

win = randomWindow2d(size(I),"Scale",[0.02 0.13],"DimensionRatio",[1 1;1 1]);

Determine the height and width of the erase region.

hwin = diff(win.YLimits)+1;
wwin = diff(win.XLimits)+1;

Erase the pixels within the erase region. Fill each pixel with a random color.

J = imerase(I,win,"FillValues",randi([1 255],[hwin wwin 3]));

Display the erased image.

imshow(J)

Input Arguments

I — Image with region to be erased

numeric matrix | numeric array

Image with a region to be erased, specified as a numeric matrix representing a grayscale image or a numeric array with three channels representing a color image.

rect — Size and position of erase rectangle

4-element numeric vector | Rectangle object

Size and position of the erase rectangle, specified as a 4-element numeric vector of the form [xmin ymin width height] or a Rectangle object.

fillValues — Fill value

0 (default) | numeric scalar | 3-element numeric vector | numeric matrix | numeric array

Fill value to apply to erased pixels, specified as one of these values.

Fill Value	Result
numeric scalar	Fill erased pixels of a grayscale or RGB image with the specified gray value.
3-element numeric vector	Fill erased pixels of an RGB image with the specified color.
numeric matrix	Fill each erased pixel of a grayscale or RGB image with the corresponding gray value in fillValue. The matrix specified by fillValue must have the same height and width as the erase rectangle, rect.
numeric array with 3 planes	Fill each erased pixel of an RGB image with the color in the corresponding pixel of fillValue. The array specified by fillValue must have the same height and width as the erase rectangle, rect.

Output Arguments

Ierased — Image with erased region

numeric matrix | numeric array

Image with erased region, returned as a numeric matrix or numeric array of the same size as the input image, I.

Version History

Introduced in R2021a