The image was taken by a russian photographer in the early 1900s using one of the early color cameras.
Scale mat image.
Here is an example for a single channel grey scale image type 8uc1 and pixel coordinates x and y.
Dst a mat object representing the destination output image for this operation.
Fx a variable of the type double representing the scale factor along the horizontal axis.
An image cannot be resized or rescaled inplace in opencv.
The code below illustrates these operations on both data types.
The image on the left is part of a historic collection of photographs called the prokudin gorskii collection.
Because the data range of the matrix is outside the default display range of imshow every pixel with a positive value displays as white and every pixel with a negative or zero value displays as black it is challenging to see the edges of the.
Intensity val 0 contains a value from 0 to 255.
If scale is in the range 0 1 b is smaller than a.
Display the result of the operation.
Cv2 resize along width or horizontal axis cv2 resize image vertically.
Width of the output image remains unchanged from that of the source image.
If a has more than two dimensions imresize only resizes the first two dimensions.
Src a mat object representing the source input image for this operation.
You will need to create another image with the new size or scale and apply a resize operation.
B imresize a scale returns image b that is scale times the size of a the input image a can be a grayscale rgb or binary image.
In the following example we will scale the image only along y axis or vertical axis.
Providing a value 100 downscales the image provided.
Resizing or rescaling a mat is somewhat easier than dealing with a iplimage.
The image on the right.
Setting and getting pixel values of a gray image in c.
Since in opencv images are represented by the same structure as matrices we use the same convention for both cases the 0 based row index or y.
In the following example scale percent value holds the percentage by which image has to be scaled.
Note that the matrix has data type double with values outside of the range 0 1 including negative values.
The color channels of the image are misaligned because of the mechanical nature of the camera.
Note the ordering of x and y.