Uchar pixval cv mat elem grayimg uchar i j cv mat elem cameramatrix float 0 2 image width 0 5f.
Cv mat data.
A header and a data block.
Matrix elements are stored row by row.
As mentioned this is a key element of the library.
The underlying matrix of an image may be copied using the cv mat clone and cv mat copyto functions.
They just process elements of an array one by one or elements from multiple arrays that have the same coordinates for example array addition.
This is about how you store the pixel values.
To access multiple channel matrices you can use cv mat elem matrix.
The cv mat data structure is essentially made up of two parts.
In the previous recipe you were introduced to the cv mat data structure.
The color space refers to how we combine color components in order to code a given color.
You can select the color space and the data type used.
Element i j i 0 based row index j 0 based column index of a matrix can be retrieved or modified using cv mat elem macro.
Or use the universal filestorage i o functions to save the image to xml or yaml format.
The header contains all of the information associated with the matrix size number of channels data type and so on.
Type has the same meaning as in cvcreatemat.
Using cv mat create nrows ncols type method or the similar constructor cv mat mat nrows ncols type fill value constructor.
Here are the some popular ones.
There are many different ways to create cv mat object.
The previous recipe showed you how to access some of the attributes of this structure contained in its header for example by using cols rows or channels.
Mat data gives a pointer which refers to the original data matrix.
In the previous recipe you were introduced to the cv mat data structure.
As mentioned this is a key element of the library.
A new matrix of the specified size and specifed type will be allocated.
In this data matrix all the pixel values are stored in 1d array.