Alternate Framebuffer Type

I would like to have the option to change framebuffer types from the standard RGBA8 to RGBA16F to allow a true-edge shader (A true-edge shader is an edgetrace shader that uses the pixels distance from the camera, instead of the color.) Example: 

#version 330
uniform sampler2D InSampler;
layout(std140) uniform SamplerInfo {
    vec2 OutSize;
    vec2 InSize;
};
in vec2 texCoord;
out vec4 fragColor;
float gray(vec4 c) {
    return c.r;
}
void main(){
    vec4 color=texture(InSampler, texCoord);
    if((color.b>1.734)&&(color.b<1.736)){
        vec2 oneTexel = 1.0 / InSize;
        vec2 xTexel=vec2(oneTexel.x,0);
        vec2 yTexel=vec2(0,oneTexel.y);
        float diffx=(gray(texture(InSampler, texCoord+xTexel))-2*gray(texture(InSampler, texCoord))+gray(texture(InSampler, texCoord-xTexel)));
        float diffy=(gray(texture(InSampler, texCoord+yTexel))-2*gray(texture(InSampler, texCoord))+gray(texture(InSampler, texCoord-yTexel)));
        float cmulta=max(min(max(diffx,diffy)/0.005/gray(texture(InSampler, texCoord)),1),0);
        if(cmulta<0.5){
            cmulta=0;
        }
        float cmultb=max(min(-min(diffx,diffy)/0.005/gray(texture(InSampler, texCoord)),1),0);
        if(cmultb<0.5){
            cmultb=0;
        }
        if((cmulta>0.5)||(cmultb>0.5)){
        fragColor=vec4(1*cmulta,1*cmultb,1,1);
        }else{
            fragColor=vec4(0,0,0,1);
        }
    }else{
        fragColor=color;
    }
}