Multi-resolution Seamless Image Database

import magic
# Libmagic will reliably detect the 'msid' signature for MrSID files
print(magic.from_file('satellite_map.sid', mime=True)) # Outputs 'image/x-mrsid-image' or similar custom MIME

const fs = require('fs');
// Manually detecting the 'msid' 4-byte signature
const buffer = Buffer.alloc(4);
const fd = fs.openSync('satellite_map.sid', 'r');
fs.readSync(fd, buffer, 0, 4, 0);
fs.closeSync(fd);
const isMrSID = buffer.toString('ascii') === 'msid';
console.log('Is Extensis MrSID:', isMrSID);

import (
    "bytes"
    "net/http"
)
// Native Go HTTP detection will default to application/octet-stream.
// Check directly for the explicit 4-byte signature:
// isMrSID := bytes.HasPrefix(buf, []byte("msid"))

$mime = mime_content_type('satellite_map.sid');
echo $mime; // Without custom GIS magic definitions, this will resolve to 'application/octet-stream'