Fix compiler problems:

We couldn't automatically cast IPixels to floats under GCC, so just
add explicit comparison operators for these pixels so that they work
with the googletest macros.

Base/include/FasTC/IPixel.h

@@ -79,6 +79,14 @@ class IPixel : public VectorBase<float, 1> {
   void Unpack(uint32 rgba);
 
   void MakeOpaque() { /* Do nothing.. */ }
+
+  bool operator==(const IPixel &other) const {
+    return static_cast<float>(*this) == static_cast<float>(other);
+  }
+
+  bool operator!=(const IPixel &other) const {
+    return static_cast<float>(*this) != static_cast<float>(other);
+  }
 };
 REGISTER_VECTOR_TYPE(IPixel);
 

Base/test/TestImage.cpp

@@ -265,7 +265,7 @@ TEST(Image, IDCT) {
   // First make sure they're different
   for (uint32 j = 0; j < h; ++j) {
     for (uint32 i = 0; i < w; ++i) {
-      EXPECT_PRED2(std::not_equal_to<float>(), img(i, j), orig(i, j));
+      EXPECT_NE(img(i, j), orig(i, j));
     }
   }