My problem is that when I use
to copy a texture from the frame buffer to update it, the new texture is greather than the original.
somebody knows why it happens?

If the original texture is smaller that the sub one, it’s normal.

The original texture and the final texture are the same.
I´m trying to render a texture using glCopyTexSubImage2D or glCopyTexImage2D, but the new updated texture is bigger than the original.
I don´t know what happens :’( with my code.
I have a 300x300 window and my texture is 256x256. I show my texture first and it´s ok. Then, I try to render it. I do this:

glBindTexture(GL_TEXTURE_2D, texture[0]);

It wont shring your 300300 window into a 256256 texture. its just going to take the lower 256*256 pixels and transfer them to the texture, and it will look bigger

Try this :

32,32 ==> The position to add the texture

glTexSubImage2D(GL_TEXTURE_2D, 0, 32, 32, pTextureImage->sizeX,
pTextureImage->sizeY, GL_RGB, GL_UNSIGNED_BYTE, pTextureImage->data);

Thanks for your replies, it´s just fixed!!!
I change the window size to 256x256 and it works jjjj.

Now I have two textures:
texture[0] and texture[1]

With glCopyTexSubImage2D(GL_TEXTURE_2D,0,0,0,0,0,256,256), I change the texture previously selected with the function glBindTexture(GL_TEXTURE_2D, texture[1])

I want my texture[1] was the original texture.