Creating a mat object explicitly.
Create cv mat c.
Mat l 3 arr cv 8uc 1 scalar all 0.
A new matrix of the specified size and specifed type will be allocated.
This method allocates data for a matrix if it is empty.
Cv 8uc1 means 8 bit single channel matrix cv 32fc2 means 2 channel i e.
We can create a matrix with more than two dimensions.
The name starts with a lower or upper case character hence a value between a z or a z.
Possible parameter names for matrix cv mat.
Each implementation calls mat create for a destination matrix.
Type has the same meaning as in cvcreatemat function e g.
Here are the some popular ones.
There are many different ways to create cv mat object.
N dimensional dense array class.
You can do this using the operator of mat.
This type is very similar to inputarray except that it is used for input output and output function parameters.
It can be used to store real or complex valued vectors and matrices grayscale or color images voxel volumes vector fields point clouds tensors histograms though very high dimensional histograms may be better stored in a sparsemat.
The sample below shows how to create a bgra image how to set custom compression parameters and save it to a png file.
The first character of the name can be followed by an infinite number of alpha numerical characters including characters like or.
Complex floating point matrix etc.
Do not explicitly create outputarray instances applies here too.
The parameters which you add to the cv mat must have a name which fits to the following rules.
Be aware that this only works for two dimensional matrices.
We can use array to initialize the constructor.
To the contrary with c api where an output image had to be created by the developer an empty output mat can be supplied to each function.
Using cv mat create nrows ncols type method or the similar constructor cv mat mat nrows ncols type fill value constructor.
Or use the universal filestorage i o functions to save the image to xml or yaml format.
If the format depth or channel order is different use mat convertto and cv cvtcolor to convert it before saving.
If you want to make your function polymorphic i e.
In the load modify and save an image tutorial you have already learned how to write a matrix to an image file by using the cv imwrite function.
The class mat represents an n dimensional dense numerical single channel or multi channel array.
The same limitation as for inputarray.
Int arr 3 4 3 2.