This code mostly works, but the resulting data seems to loose a color channel (is what I am thinking) as the resulting image data when displayed is tinted blue!
Here
Just to clarify the answer above: I've ran into the same issue because my shader code was expecting two layered samples within a image buffer, while I used a single layer buffer
This line took the rgb values from one sample and passed them to (I don't know what), but the end result is full colored image.
gl_FragColor = vec4(texture2D(SamplerY, texCoordVarying).rgb, 1);