png image blurry when loaded onto texture

Question

I have created a png image in photoshop with transparencies that I have loaded into and OpenGL program. I have binded it to a texture and in the program the picture looks blurry and I'm not sure why.

alt text http://img685.imageshack.us/img685/9130/upload2.png

alt text http://img695.imageshack.us/img695/2424/upload1e.png

Loading Code

// Texture loading object
nv::Image title;

// Return true on success
if(title.loadImageFromFile("test.png"))
{
    glGenTextures(1, &titleTex);
    glBindTexture(GL_TEXTURE_2D, titleTex);
    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
    glTexImage2D(GL_TEXTURE_2D, 0, title.getInternalFormat(), title.getWidth(), title.getHeight(), 0, title.getFormat(), title.getType(), title.getLevel(0));
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, 16.0f);
}

else
    MessageBox(NULL, "Failed to load texture", "End of the world", MB_OK | MB_ICONINFORMATION);

Display Code

glEnable(GL_TEXTURE_2D);    
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glBindTexture(GL_TEXTURE_2D, titleTex);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
glTranslatef(-800, 0, 0.0);
glColor3f(1,1,1);

glBegin(GL_QUADS);
    glTexCoord2f(0.0, 0.0); glVertex2f(0,0);
    glTexCoord2f(0.0, 1.0); glVertex2f(0,600);
    glTexCoord2f(1.0, 1.0); glVertex2f(1600,600);
    glTexCoord2f(1.0, 0.0); glVertex2f(1600,0);
glEnd();
glDisable(GL_BLEND);    
glDisable(GL_TEXTURE_2D);

EDIT: I don't think i'm stretching each pixel should be two in the co-ordinate system

int width=800, height=600;
int left = -400-(width-400);
int right = 400+(width-400);
int top = 400+(height-400);
int bottom = -400-(height-400);
gluOrtho2D(left,right,bottom,top);

Answer 1

OpenGL will (normally) require that the texture itself have a size that's a power of 2, so what's (probably) happening is that your texture is being scaled to a size where the dimensions are a power of 2, then it's being scaled back to the original size -- in the process of being scaled twice, you're losing some quality.

You apparently just want to display your bitmap without any scaling, without wrapping it to the surface of another object, or anything like that (i.e., any of the things textures are intended for). That being the case, I'd just display it as a bitmap, not a texture (e.g. see glRasterPos2i and glBitmap).