How to obtain an array of hexadecimal codes from an image?

Question

I need to convert a .bmp image to a hex array in PHP.

I have tried to create a function for this but it has not worked

function bmp_to_hex($filename) {   
    $bmp = file_get_contents($filename);   
    $output = '';   
    for($i=0; $i < strlen($bmp); $i++) {     
        $output .= dechex(ord($test{$i}));   
    }   
    return $output; 
}

Is there a function in PHP for this? If not, how should I do?

Thanks in advance.

Answer 1

There is no ready-made function for it. You can do the following:

function bmp_to_hex($filename) {   
  $bmpStr = file_get_contents($filename);   
  $hexStr = bin2hex($bmpStr);
  $hexArray = str_split($hexStr,2);
  return $hexArray;
}

The $bmpStr ist a string like "BMF>(..". $hexStr is a string like "424d460000 .." with the 2-character values. An array is then created with str_split. The array then starts like this: {[0] => string (2) "42" [1] => string (2) "4d".

Note: Bitmaps can get very large. $hexStr becomes twice as large. The array of these then requires a very huge amount of memory.