The most common types are.
Can pixel value be 0 cv mat c.
Cv 8uc3 for 8 bit 3 channel color images.
For this example let s draw a red pixel at position 100 50.
I m afraid iterating over the image pixels and updating the underneath matrix will update only the last iteration.
Opencv efficient pixel access using cv mat ptr pointer example if efficiency is important a fast way to iterate over pixels in a cv mat object is to use its ptr t int r method to obtain a pointer to the beginning of row r 0 based index.
Pixel access for cv mat in case cheat sheet is not clear enough.
Cv 8uc1 for 8 bit 1 channel grayscale images.
To access pixel values in an opencv cv mat object you first have to know the type of your matrix.
In order to access matrices some template methods do exist but this means it is necessary to pass the data type to the method when accessing the element value specified by the indexes i j.
Thread i understand that max element return iterators not values.
Shai it seems a good idea initially it probably is faster from the performance point of view since it s guaranteed to store unique values.
The pixels array is stored in the data attribute of cv mat.
Cv 32fc1 for 32 bit floating point 1 channel grayscale images.
Cv 32fc3 for 32 bit floating point 3 channel color images.
This is why i use maxvalue.
How can i do something similar in gocv.
It renders useless the std find i placed in the code and it will br great if your cv mat is single channel and you need to store an integer however if you need to store cv vec3b a pixel or other complex data types std vector might be better.
One way i have tried is using the setto method and providing a scalar as parameter but there is no way i can tell with this method which pixel value i want to update something like setto x y sclarvalue is there something i m missing.
Maxvalue is always returning 0.
The default setting with cv imread will.
Let s suppose that we have a mat matrix where each pixel has 3 bytes cv 8uc3.
Create a macro function that obtains the pixel from the array.
