gray_img = imread('pout.tif');
imhist(gray_img);
title('Histogram of a Low-Contrast Image');Output: A figure window with a bar chart showing the intensity distribution of the 'pout.tif' image.
#12.
histeq()Enhances contrast using histogram equalization.
low_contrast_img = imread('pout.tif');
high_contrast_img = histeq(low_contrast_img);
imshow(high_contrast_img);
title('Histogram Equalized Image');Output: A figure window displays a higher contrast version of the 'pout.tif' image.
#13.
imadjust()Adjusts image intensity values or colormap by mapping intensity values to new values.
img = imread('cameraman.tif');
adjusted_img = imadjust(img, [0.3 0.7], []);
imshow(adjusted_img);
title('Intensity Adjusted Image');Output: A figure window showing a high-contrast version of the cameraman image, where intensities between 0.3 and 0.7 are stretched to the full [0, 1] range.
#14.
imtranslate()Translates (shifts) an image horizontally and vertically.
img = imread('cameraman.tif');
translated_img = imtranslate(img, [25, 15]); % Shift 25 pixels right, 15 pixels down
imshow(translated_img);
title('Translated Image');Output: A figure window shows the cameraman image shifted to the right and down.
#15.
imsharpen()Sharpens an image using the unsharp masking method.
img = imread('peppers.png');
sharpened_img = imsharpen(img);
imshow(sharpened_img);
title('Sharpened Image');Output: A figure window displays a crisper, more detailed version of the peppers image.
---
#MATLAB #ImageProcessing #Filtering #Noise
#16.
imnoise()Adds a specified type of noise to an image.
img = imread('cameraman.tif');
noisy_img = imnoise(img, 'salt & pepper', 0.02);
imshow(noisy_img);
title('Image with Salt & Pepper Noise');Output: A figure window displays the cameraman image with random white and black pixels (noise).
#17.
fspecial()Creates a predefined 2-D filter kernel (e.g., for averaging, Gaussian blur, Laplacian).
h = fspecial('motion', 20, 45); % Create a motion blur filter
disp('Generated a 2D motion filter kernel.');
disp(h);Generated a 2D motion filter kernel.
(Output is a matrix representing the filter kernel)
#18.
imfilter()Filters a multidimensional image with a specified filter kernel.
img = imread('cameraman.tif');
h = fspecial('motion', 20, 45);
motion_blur_img = imfilter(img, h, 'replicate');
imshow(motion_blur_img);
title('Motion Blurred Image');Output: A figure window shows the cameraman image with a motion blur effect applied at a 45-degree angle.
#19.
medfilt2()Performs 2-D median filtering, which is excellent for removing 'salt & pepper' noise.
noisy_img = imnoise(imread('cameraman.tif'), 'salt & pepper', 0.02);
denoised_img = medfilt2(noisy_img);
imshow(denoised_img);
title('Denoised with Median Filter');Output: A figure window shows the noisy image significantly cleaned up, with most salt & pepper noise removed.
#20.
edge()Finds edges in an intensity image using various algorithms (e.g., Sobel, Canny).
img = imread('cameraman.tif');
edges = edge(img, 'Canny');
imshow(edges);
title('Edges found with Canny Detector');Output: A figure window displays a binary image showing only the detected edges from the original image in white.
---
#MATLAB #ImageProcessing #Segmentation #Morphology
#21.
graythresh()Computes a global image threshold from a grayscale image using Otsu's method.
img = imread('coins.png');
level = graythresh(img);
disp(['Optimal threshold level (Otsu): ', num2str(level)]);Optimal threshold level (Otsu): 0.49412
#22.
imbinarize()Converts a grayscale image to a binary image based on a threshold.
img = imread('coins.png');
level = graythresh(img); % Find optimal threshold
bw_img = imbinarize(img, level);
imshow(bw_img);
title('Binarized Image (Otsu Method)');Output: A figure window displays a black and white image of the coins.
#23.
strel()Creates a morphological structuring element (SE), which is used to probe an image in morphological operations.
se = strel('disk', 5);
disp('Created a disk-shaped structuring element with radius 5.');
disp(se);Created a disk-shaped structuring element with radius 5.
(Output describes the strel object and shows its matrix representation)
#24.
imdilate()Dilates a binary image, making objects larger and filling small holes.
img = imread('text.png');
se = strel('line', 3, 90); % A vertical line SE
dilated_img = imdilate(img, se);
imshow(dilated_img);
title('Dilated Text');Output: A figure window shows the text characters appearing thicker, especially in the vertical direction.
#25.
imerode()Erodes a binary image, shrinking objects and removing small noise.
img = imread('text.png');
se = strel('line', 3, 0); % A horizontal line SE
eroded_img = imerode(img, se);
imshow(eroded_img);
title('Eroded Text');Output: A figure window shows the text characters appearing thinner, with horizontal parts possibly disappearing.
---
#MATLAB #ImageProcessing #Analysis
#26.
imopen()Performs morphological opening (erosion followed by dilation). It smooths contours and removes small objects.
original = imread('circbw.tif');
se = strel('disk', 10);
opened_img = imopen(original, se);
imshow(opened_img);
title('Morphologically Opened Image');Output: A figure window displays the image with small protrusions removed and gaps between objects widened.
#27.
bwareaopen()Removes all connected components (objects) from a binary image that have fewer than a specified number of pixels.
img = imread('text.png');
cleaned_img = bwareaopen(img, 50); % Remove objects with fewer than 50 pixels
imshow(cleaned_img);
title('Image after removing small objects');Output: A figure window shows the text image with small noise specks or broken parts of characters removed.
#28.
bwlabel()Labels connected components in a binary image.
img = imread('text.png');
[L, num] = bwlabel(img);
disp(['Number of connected objects found: ', num2str(num)]);Number of connected objects found: 114
#29.
regionprops()Measures a set of properties for each labeled region in an image.