Cv Mat Data

You can select the color space and the data type used.

Cv mat data. Some operations like the one above do not actually depend on the array shape. In this data matrix all the pixel values are stored in 1d array. In the previous recipe you were introduced to the cv mat data structure. This is about how you store the pixel values.

The underlying matrix of an image may be copied using the cv mat clone and cv mat copyto functions. As mentioned this is a key element of the library. There are many different ways to create cv mat object. Uchar pixval cv mat elem grayimg uchar i j cv mat elem cameramatrix float 0 2 image width 0 5f.

They just process elements of an array one by one or elements from multiple arrays that have the same coordinates for example array addition. As mentioned this is a key element of the library. To access multiple channel matrices you can use cv mat elem matrix. Mat data gives a pointer which refers to the original data matrix.

Using cv mat create nrows ncols type method or the similar constructor cv mat mat nrows ncols type fill value constructor. 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. Matrix elements are stored row by row. A header and a data block.

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. If the format depth or channel order is different use mat convertto and cv cvtcolor to convert it before saving. The cv mat data structure is essentially made up of two parts. A new matrix of the specified size and specifed type will be allocated.

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. Multiple images vector of mat can be saved in tiff format see the code sample below. Type has the same meaning as in cvcreatemat.