Is it good practice to use std::vector as a simple buffer?

Question

I have an application that is performing some processing on some images.

Given that I know the width/height/format etc. (I do), and thinking just about defining a buffer

Answer 1

In addition - to ensure a minimum of allocated memory:

void MyClass::OnImageReceived(unsigned char *pPixels, unsigned int uPixelCount)
{
    m_pImageBuffer.swap(std::vector(
         pPixels, pPixels + uPixelCount));
    // ... process image etc. ...
}

vector::assign does not change the amount of memory allocated, if the capacity is bigger than the amount needed:

Effects: erase(begin(), end()); insert(begin(), first, last);