C++ EasyBMP Pointer Issue - c++

Question

The following code is causing a Segmentation Fault on the .ReadFromFile line:
int main()
{
// Load in.bmp
BMP * original;
cout << "line " << __LINE__ << ": Got here!" << endl;
original->ReadFromFile("in.bmp"); //Error HERE!
int width = original->TellWidth();
int height = original->TellHeight();
cout << "line " << __LINE__ << ": Got here!" << endl;
I'm using the EasyBMP library, which is included above the main function. I know it has something to do with memory and pointers, but I can't figure out what to use in place of "original->"... I've tried (*original). and (&original). but I can't seem to get it. Any help?
Thanks!

Answer 1

Your pointer original is pointing to a random memory location. Trying to use it will cause the undefined behavior. You need to allocate memory for BMP object and store the address in this pointer. If you want your object to persist even after it goes out of the function use original = new BMP();(don't forget to delete it later though) else you can directly do BMP original; and use it.

Answer 2

You have declared BMP as a pointer but never initialized it.
Try using:
BMP original;
or
BMP *original = new BMP();
The first method will create original on the stack, and you won't have to release it. The second method creates it in the free-store, and you need to use delete to free it.
delete original;

Answer 3

According to the tutorial, your code should be:
BMP Image;
Image.ReadFromFile( argv[3] );

Answer 4

It is not necessary to use a pointer try this:
// Load in.bmp
BMP original;
cout << "line " << __LINE__ << ": Got here!" << endl;
original.ReadFromFile("in.bmp"); //Error HERE!
int width = original.TellWidth();
int height = original.TellHeight();
cout << "line " << __LINE__ << ": Got here!" << endl;
or if you need to use the heap do:
BMP* original = new BMP();
and when you are done don't forget to free the memory
delete original;