adding Go port

go/README.md

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+# Mixbox-Go
+
+Below is a sample README.md you could use for your Go implementation. You can adjust the wording to suit your style.
+
+---
+
+```markdown
+# Mixbox for Go
+
+This repository provides a Go implementation of the Mixbox pigment mixing model, originally described in the SIGGRAPH 2021 paper ["Practical Pigment Mixing for Digital Painting"](https://doi.org/10.1145/3478513.3480549) by Sochorová and Jamriška.  
+Mixbox simulates realistic pigment blending through a latent color space, making pigment mixing more true to real-world behavior than standard RGB linear interpolation.
+
+## Installation
+
+Initialize a Go module in your project (if you haven’t already):
+
+```bash
+go mod init github.com/timf34/mixbox-go
+```
+
+To use the Mixbox package in your project, simply add:
+
+```bash
+go get github.com/timf34/mixbox-go/mixbox
+```
+
+## Usage
+
+### Basic Color Mixing
+
+Below is a minimal example that uses the Mixbox library to linearly blend two colors (using pigment-based interpolation):
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/timf34/mixbox-go/mixbox"
+)
+
+func main() {
+	rgb1 := [3]uint8{0, 33, 133}   // e.g. blue
+	rgb2 := [3]uint8{252, 211, 0}   // e.g. yellow
+	t := 0.5                      // mixing ratio
+
+	// Performs pigment mixing using the latent space interpolation.
+	rgbMix := mixbox.Lerp(rgb1, rgb2, t)
+	fmt.Printf("Mixed color: %d %d %d\n", rgbMix[0], rgbMix[1], rgbMix[2])
+}
+```
+
+### Mixing Multiple Colors
+
+You can perform multi-color blending by converting RGB colors to their latent representations, mixing them with weighted contributions, and finally converting back to RGB. For example:
+
+```go
+package main
+
+import (
+	"fmt"
+	"github.com/timf34/mixbox-go/mixbox"
+)
+
+func main() {
+	// Example colors
+	rgb1 := [3]uint8{254, 236, 0}  // Cadmium Yellow
+	rgb2 := [3]uint8{255, 39, 2}    // Cadmium Red
+	rgb3 := [3]uint8{25, 0, 89}     // Ultramarine Blue
+
+	// Convert each color into the latent representation.
+	latent1 := mixbox.RGBToLatent(rgb1)
+	latent2 := mixbox.RGBToLatent(rgb2)
+	latent3 := mixbox.RGBToLatent(rgb3)
+
+	var latentMix [mixbox.LatentSize]float64
+
+	// Mix with weights 0.3, 0.6, and 0.1 respectively.
+	for i := 0; i < mixbox.LatentSize; i++ {
+		latentMix[i] = 0.3*latent1[i] + 0.6*latent2[i] + 0.1*latent3[i]
+	}
+
+	// Convert the mixed latent representation back to RGB.
+	rgbMix := mixbox.LatentToRGB(latentMix)
+	fmt.Printf("Multi-color mixed result: %d %d %d\n", rgbMix[0], rgbMix[1], rgbMix[2])
+}
+```
+
+### Running the Demo: Gradient Comparison
+
+A demo application is provided in `main.go` that generates a PNG image (`gradient.png`). It compares Mixbox blending against standard linear RGB mixing. To run the demo, execute:
+
+```bash
+go run main.go
+```
+
+The demo loads the pigment lookup table (LUT) from `lut.dat` (or you can use the provided string-based decompression helper) and creates an image where the top half shows Mixbox (pigment-based) blending and the bottom half shows linear RGB interpolation.
+
+## LUT Initialization
+
+The library supports two approaches to initialize the LUT:
+
+1. **From a Binary File:**  
+   The demo (in `main.go`) uses:
+   ```go
+   err := mixbox.LoadLUTFromFile("lut.dat")
+   ```
+2. **From a Raw Encoded String:**  
+   You can also decompress a base64-encoded, deflate-compressed string (as in the Python implementation) via:
+   ```go
+   err := mixbox.DecompressAndInitLUT("xNrFmuTYEQXgV5mtmZn5AcbMzDRcK")
+   ```
+
+Choose the method that best suits your distribution or integration needs.
+
+## Pigment Colors
+| Pigment |  | RGB | Float RGB | Linear RGB |
+| --- | --- |:----:|:----:|:----:|
+| Cadmium Yellow | <img src="https://scrtwpns.com/mixbox/pigments/cadmium_yellow.png"/> | 254, 236, 0  | 0.996, 0.925, 0.0 | 0.991, 0.839, 0.0 |
+| Hansa Yellow | <img src="https://scrtwpns.com/mixbox/pigments/hansa_yellow.png"/> | 252, 211, 0  | 0.988, 0.827, 0.0 | 0.973, 0.651, 0.0 |
+| Cadmium Orange | <img src="https://scrtwpns.com/mixbox/pigments/cadmium_orange.png"/> | 255, 105, 0  | 1.0, 0.412, 0.0 | 1.0, 0.141, 0.0 |
+| Cadmium Red | <img src="https://scrtwpns.com/mixbox/pigments/cadmium_red.png"/> | 255, 39, 2  | 1.0, 0.153, 0.008 | 1.0, 0.02, 0.001 |
+| Quinacridone Magenta | <img src="https://scrtwpns.com/mixbox/pigments/quinacridone_magenta.png"/> | 128, 2, 46  | 0.502, 0.008, 0.18 | 0.216, 0.001, 0.027 |
+| Cobalt Violet | <img src="https://scrtwpns.com/mixbox/pigments/cobalt_violet.png"/> | 78, 0, 66  | 0.306, 0.0, 0.259 | 0.076, 0.0, 0.054 |
+| Ultramarine Blue | <img src="https://scrtwpns.com/mixbox/pigments/ultramarine_blue.png"/> | 25, 0, 89  | 0.098, 0.0, 0.349 | 0.01, 0.0, 0.1 |
+| Cobalt Blue | <img src="https://scrtwpns.com/mixbox/pigments/cobalt_blue.png"/> | 0, 33, 133  | 0.0, 0.129, 0.522 | 0.0, 0.015, 0.235 |
+| Phthalo Blue | <img src="https://scrtwpns.com/mixbox/pigments/phthalo_blue.png"/> | 13, 27, 68  | 0.051, 0.106, 0.267 | 0.004, 0.011, 0.058 |
+| Phthalo Green | <img src="https://scrtwpns.com/mixbox/pigments/phthalo_green.png"/> | 0, 60, 50  | 0.0, 0.235, 0.196 | 0.0, 0.045, 0.032 |
+| Permanent Green | <img src="https://scrtwpns.com/mixbox/pigments/permanent_green.png"/> | 7, 109, 22  | 0.027, 0.427, 0.086 | 0.002, 0.153, 0.008 |
+| Sap Green | <img src="https://scrtwpns.com/mixbox/pigments/sap_green.png"/> | 107, 148, 4  | 0.42, 0.58, 0.016 | 0.147, 0.296, 0.001 |
+| Burnt Sienna | <img src="https://scrtwpns.com/mixbox/pigments/burnt_sienna.png"/> | 123, 72, 0  | 0.482, 0.282, 0.0 | 0.198, 0.065, 0.0 |