Finished simple compression algorithm

com.unity.render-pipelines.high-definition/HDRP/Debug/DebugColorPicker.shader

 
                 float4 result = SAMPLE_TEXTURE2D(_DebugColorPickerTexture, sampler_DebugColorPickerTexture, input.texcoord);
 
+                //Decompress value if luxMeter is active
-                    result.rgb = exp2(result.rgb) - 2;
+                    result.rgb = result.rgb * LUXMETER_COMPRESSION_RATIO;
 
                 if (_FalseColor)
                     result.rgb = FasleColorRemap(Luminance(result.rgb), _FalseColorThresholds);
                     }
 
                     float4 mouseResult = SAMPLE_TEXTURE2D(_DebugColorPickerTexture, sampler_DebugColorPickerTexture, mousePixelCoord.zw);
+                    
+                    //Decompress value if luxMeter is active
+                    if (_DebugLightingMode == DEBUGLIGHTINGMODE_LUX_METER)
+                        mouseResult = mouseResult * LUXMETER_COMPRESSION_RATIO;
+
-                    
-                    if (_DebugLightingMode == DEBUGLIGHTINGMODE_LUX_METER)
-                        mouseResult = exp2(mouseResult) - 2;
 
                     result = DisplayPixelInformationAtMousePosition(input, result, mouseResult, mousePixelCoord);
                 }

com.unity.render-pipelines.high-definition/HDRP/Debug/DebugDisplay.hlsl

 float _DebugExposure;
 CBUFFER_END
 
+#define LUXMETER_COMPRESSION_RATIO  4
+
 TEXTURE2D(_DebugFont); // Debug font to write string in shader
 RWStructuredBuffer<ScreenSpaceTracingDebug> _DebugScreenSpaceTracingData : register(u7); // TODO: Change the register number for PS4
 

com.unity.render-pipelines.high-definition/HDRP/Material/Lit/Lit.hlsl

         case DEBUGLIGHTINGMODE_LUX_METER:
             diffuseLighting = lighting.direct.diffuse + bakeLightingData.bakeDiffuseLighting;
 
+            //Compress lighting values for color picker if enabled
-                diffuseLighting = log2(diffuseLighting + 2);
+                diffuseLighting = diffuseLighting / LUXMETER_COMPRESSION_RATIO;
             
             specularLighting = float3(0.0, 0.0, 0.0); // Disable specular lighting
             break;