Matlab axis problems

Matlab axis problems

In summary terms

Row Óyó High Ó vertical

Column Óxó width ó level

2 photos in Maplab

1. Jpg

Width (column): 320 high (ROW): 482

Show in MATLAB

2. Jpg

Width (column): 480 High (ROW): 360

First of all to clarify the two concepts: the processing object is a picture or a corresponding matrix (true color image return 3-dimensional matrix, gray value image return two-dimensional matrix)

If the object being processed is a picture, the following concepts are involved

1) coordinates origin: upper left corner

2) X: Horizontal Direction

3) Y: Vertical Direction

4) Image size: Width: Horizontal Height: Vertical direction

If the object being processed is a matrix, the following concepts are involved

1) Line: Vertical direction equivalent to Y

2) Column: Horizontal direction equivalent to X

Example

One processing object for picture

1.

>> imfinfo (' 1.jpg ')

Get:

width:320

height:482

>> imfinfo (' 2.jpg ')

width:480

height:360

2. Image clipping

I2=imcrop (I,rect) and RECT is an optional parameter,

The format is [XMIN ymin wigth HEIGHT]. For example [20 20 40 40], the upper-left pixel of the cropped image is the pixels of the original image position (20,20), and the lower-right pixel of the cropped image is the pixels of the original image position (60,60).

>>imshow (B)

>> C=imcrop (b,[300,5,200,100]);

>> Imshow (C)

Get:

The second processing object is a matrix

1) Size

True Color Image Returns a 3-dimensional matrix, grayscale value image returns two-dimensional matrix

Two-dimensional matrix matlab size (A): Returns row x column

Three-dimensional matrix matlab size (A): Returns the row x column x3,3 represents the color channel

>> a=imread (' 1.jpg ');

>> b=imread (' 2.jpg ');

>> size (A)

Ans =

482 320 3

>> size (B)

Ans =

360 480 3

2) Imresize

B = Imresize (A, [NumRows Numcols])

NumRows and Numcols Specify the height and width of the target image, respectively. It is obvious that because this format allows image scaling and the length-to-width ratio of the source image is not the same, the resulting image may be distorted.

>> Resize1=imresize (a,[50 500]);

>> Imshow (RESIZE1)

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Matlab axis problems