Trouble getting texture pixels Not to repeat at the edge - opengl-es-2.0

Question

Not familiar with OpenGL, and cannot seem to figure out this small detail. I keep finding information on repeats of a texture and not border elements.
When zooming in on a texture, the edge pixels on the end are repeated to the edge of the surface view that I am working on. I would rather see a clear background behind those pixels when the texture is smaller than the view.
I can assume that it has to do with setting attributes to my texture around these lines of the code, but I just can't follow it enough to understand what changes to make to get the desired result.
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
Aide on the (most likely quick modification) topic for getting that desired result would put my current issue to rest.

Answer 1

Ok, I'll try to explain.
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
The GL_TEXTURE_MIN_FILTER is the filter applied when a texture's bitmap dimension in larger than the drawing surface's corresponding dimension. GL_TEXTURE_MAG_FILTER is the opposite. So this is not the problem.
GL_TEXTURE_WRAP_S and GL_TEXTURE_WRAP_T however, define what to do when a texture coordinate falls outside of the 0.0 to 1.0 range (For both axis). You have them both set to GL_CLAMP_TO_EDGE, which basicly means that if a texture coordinate < 0 then use 0, if > 1 use 1. This is basicly what you see happening in your picture.
However, this can only be changed to GL_REPEAT which repeats the texture or GL_MIRRORED_REPEAT which repeats and mirrors. So your problem can not be fixed by changing these settings. There is no discard-if-out-of-range setting, which I think you need.
You can read more about this in the documentation if you please: http://www.khronos.org/opengles/sdk/docs/man/
I don't know exactly how you zoom, but it usually doesn't involve changing texture coordinates as far as I know. If you want to keep it this way, you could try a little hack though - in the the fragment shader you could add before setting the gl_FragColor:
if (tc.x < 0.0 || tc.x > 1.0 || tc.y < 0.0 || tc.y > 1.0 )
discard;
Where tc is your texture coordinate. So this would discard the fragment if the texture coordinate is out of the 0 to 1 range.
It's not a pretty solution, but it should do the trick.

Answer 2

Brianberg's approach would work, but scaling the quad you're rendering the image to rather than modifying texture coordinates would be a cleaner & better performing solution. There's no need to change the texture coordinates, as you always want the image to fit the quad exactly.