Interprate JPEG file according to spec

main.go

// specs -> https://www.w3.org/Graphics/JPEG/jfif3.pdf

// Suppose you have a JPEG file with the following segments:
// SOI (Start of Image): FFD8
// APP0 (JFIF): FFE0 followed by length and JFIF metadata
// DQT (Quantization Table): FFDB followed by length and quantization table data
// SOF0 (Baseline DCT): FFC0 followed by length and frame information
// DHT (Huffman Table): FFC4 followed by length and Huffman tables
// SOS (Start of Scan): FFDA followed by length and scan parameters
// Compressed Image Data: Huffman-encoded DCT coefficients
// EOI (End of Image): FFD9

// [SOI] [APP0/APP1] [DQT] [SOF] [DHT] [DRI] [SOS] [Compressed Data] [EOI]

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io"
	"os"
)

func main() {
	f, err := os.Open("my-jpeg-file-path")
	if err != nil {
		panic(err)
	}

	br := bufio.NewReader(f)

	prev := ""

	for {
		b, err := br.ReadByte()

		if err != nil && !errors.Is(err, io.EOF) {
			fmt.Println(err)
			break
		}

		prev = prev + fmt.Sprintf("%02X", b)

		if len(prev) == 4 {
			fmt.Printf("0x%s\n", prev)
			prev = ""
		}

		if err != nil {
			break
		}
	}
}