Question Deform objects

Good afternoon.
I created a shader to pixelate an image.
Now I want to deform the pixels into a X shape.

Pixelated Image:





I want them to be deformed like this:


Code:

Code (CSharp):

1.  
2. float4 GetSource(float2 fxUV) {
3.     return SAMPLE_TEXTURE2D(_PostFXSource, sampler_PostFXSource, fxUV);
4. }
5.  
6. float lightIntensity(float2 fxUV, float thr) {
7.     float4 colorChannel = GetSourceThreshold(fxUV, thr);
8.     colorChannel = (pow(colorChannel, 4) * 2) / 333;
9.     float greyscale = (colorChannel.r + colorChannel.g + colorChannel.b) / 3.0f;
10.     return greyscale;
11. }
12.  
13. float4 frag(Varyings i) : SV_Target
14. {
15.  
16.                 float4 colorChannel = GetSource(i.fxUV);
17.                 float2 uvFX = i.fxUV.xy;
18.  
19.                 float4 result = float4(0, 0, 0, 0);
20.                
21.                     uvFX.x *= _PixelColumns;
22.                     uvFX.y *= _PixelRows;
23.  
24.                     uvFX.x = round(uvFX.x);
25.                     uvFX.y = round(uvFX.y);
26.  
27.                     uvFX.x /= _PixelColumns;
28.                     uvFX.y /= _PixelRows;
29.  
30.                     float greyscale = lightIntensity(uvFX, 1);
31.  
32.                     float4 r = float4(greyscale, greyscale, greyscale, 1);
33.                     result += normalize(r);
34.  
35.                 if (_Debug == 0)
36.                 return float4(colorChannel.rgb + result, colorChannel.a);
37.                 else {
38.                 return float4(result.rgb, 1);
39.                 }
40.  
41.              }
42.  

How can I create this effect?