Correctly render BW image

image.frag

@@ -5,10 +5,12 @@ varying vec2 qt_TexCoord0;
 uniform vec2 scale;
 uniform float a;
 uniform int stretch;
+uniform bool bw;
 
 void main(void)
 {
     vec4 color = texture2D(qt_Texture0, qt_TexCoord0);
+    if(bw)color = color.rrra;
     color = color*scale.x + scale.y;
     max(color, vec4(0.0f));