Do you see most of look of the image when we display just this component, such as objects in the image, except the color details?ĭo-It-Yourself: Use MATLAB to display and examine HSV representations of the images that you have studied in the RGB part of this lab. As Value varies from 0 to 1, the brightness increases.When Saturation is 0, the colors are unsaturated (i.e., shades of gray) When it is 1, the colors are fully saturated (i.e., they contain no white component and appear to be most solid/pure.As Hue varies from 0 to 1, the resulting color varies from red through yellow, green, cyan, blue, and magenta, and returns to red.And for the third image, the sky and sea are blue with high brightness, thus these area will highlighten in blue component. For the second image, the person wear a red coat, which will result in a large red component, and since there is a big area in the sky is white with high brightness, thus for all the componets, that area has a large value of brightness. Compare and discuss your observations in your report.įilename = ĭiscussion: As for the first image, the background is yellow, thus it is highlightened in the red and green component, and the neck of the bird is whiht, which will be highlighten in all the components, and the leather of the bird is black, which will have small brightness in all components. Use MATLAB to display and examine RGB representations of these images.

Try to include images of different characteristics, e.g., colorful objects or scenaries people etc. Use camera (or camera phone) to take three or more images, and transfer them to your computer (e.g., by email, cloud drives, or USB, etc.).For the red component, the bright area corresponds to the red and pink flowers, orange leaves and butterfly As for the green component, the bright area corresponds to the green grass and green leaves For the blue component, the bright area correponds to pink flowers and since there is few blue objects in the original figure, the overall brightness of the blue component is small. Question: Can you look at different objects of the Flower image (e.g., flowers of different colors, green leaves, and the butterfly) and make sense of the bright or dark values of the red, green and blue components?Īnswer: Fiuger(2) shows the brightness of red, green and blue components. The results of having partial color components mimic what you may see when some R/G/B pin contact of a display connector (such as the VGA traditionally on computers/laptops) becomes loose. You can change to show the results of different orders of adding up the color components. Subplot(1, 4, 4), imshow(img2), title( '3 components: RGB') Subplot(1, 4, 2), imshow(img2), title( '1 component: Blue')

Img2 = uint8( img2 ) %% ensure correct data type of unsigned 8-bit integer

Img2 = zeros( size(img1) ) %% initialize arrays of the same size as img1 Merging RGB components: figure(3), subplot(1, 4, 1), imshow(img1), title( 'Original') Subplot(2, 2, 4), imshow(img1_b), title( 'Blue'), colorbar Subplot(2, 2, 3), imshow(img1_g), title( 'Green'), colorbar Subplot(2, 2, 2), imshow(img1_r), title( 'Red'), colorbar 8-bit representation gives a scale of 0 to 255, with 0 being the darkest and 255 the brightness in the particular color component. The overall color image is thus stored in an array of three indexing variables, as you can see in the summary of Workspace in MATLAB, or run the function size.Ī R/G/B component is represented by dafault using 8 bits (unsigned 8-bit integer or 'uint8' in MATLAB data type. The horizontal and vertical dimensions of each color matrix matches the size of the image in unit of pixels. A matrix is essentially an array indexed by two indexing variables typically for row and column.Įach of the three color matrices can be specified by the third indexing number - note the number 1 in the example below img(:,:,1), and so on. In image/video processing, it is also referred to as R/G/B channels.

By default, a color image is stored by MATLAB using 3 matrices, each representing red, green and blue components of pixels.

Basic image tools matlab