Add support for invert and super pixel

image.frag

@@ -4,6 +4,7 @@ uniform sampler2D qt_Texture0;
 in vec2 qt_TexCoord0;
 uniform vec3 mtf_param;
 uniform bool bw;
+uniform bool invert;
 out vec4 color;
 
 vec4 MTF(vec4 x, vec3 m)
@@ -19,6 +20,8 @@ void main(void)
     if(bw)color = color.rrra;
     color = MTF(color, mtf_param);
 
+    if(invert)color = vec4(1.0) - color;
+
     if(any(lessThan(qt_TexCoord0, vec2(0.0))) || any(greaterThan(qt_TexCoord0, vec2(1.0))))
         color = vec4(0.0);
 }