Cv Mat Data

There are many different ways to create cv mat object.

Cv mat data.

In the previous recipe you were introduced to the cv mat data structure. In the previous recipe you were introduced to the cv mat data structure. Here are the some popular ones. The underlying matrix of an image may be copied using the cv mat clone and cv mat copyto functions.

You can select the color space and the data type used. The color space refers to how we combine color components in order to code a given color. Type has the same meaning as in cvcreatemat. Mat data gives a pointer which refers to the original data matrix.

The header contains all of the information associated with the matrix size number of channels data type and so on. In this data matrix all the pixel values are stored in 1d array. Uchar pixval cv mat elem grayimg uchar i j cv mat elem cameramatrix float 0 2 image width 0 5f. Using cv mat create nrows ncols type method or the similar constructor cv mat mat nrows ncols type fill value constructor.

As mentioned this is a key element of the library. Matrix elements are stored row by row. Some operations like the one above do not actually depend on the array shape. As mentioned this is a key element of the library.

This is about how you store the pixel values. 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. 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. Or use the universal filestorage i o functions to save the image to xml or yaml format.

The cv mat data structure is essentially made up of two parts. To access multiple channel matrices you can use cv mat elem matrix. A new matrix of the specified size and specifed type will be allocated. Multiple images vector of mat can be saved in tiff format see the code sample below.