PHP - JPEG Image to RGB value Array - php

Question

I am wanting to get an array of RGB values from an image. E.g. (2 X 2 pix example.)
[[[R, G, B], [R, G, B]], [[R, G, B], [R, G, B]]]
The code I have now:
<?php
// open an image
$image = imagecreatefromjpeg('image.jpg'); // imagecreatefromjpeg/png/
// get image dimension, define colour array
$width = imagesx($image);
$height = imagesy($image);
$colors = [];
for ($y = 0; $y < $height; $y++)
{
for ($x = 0; $x < $width; $x++)
{
$rgb = imagecolorat($image, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
}
}
print_r($colors);
?>
The above is not working.
My image is now just a 2 X 2 pix jpeg which should output:
[[[0, 255, 0], [255, 0, 0]], [[0, 0, 255], [255, 255, 255]]]
Any help greatly appreciated!

Answer 1

OK, nailed it. Thanks to all.
<?php
$image = imagecreatefromjpeg('image.jpg'); // imagecreatefromjpeg/png/
$width = imagesx($image);
$height = imagesy($image);
$colors = array();
for ($y = 0; $y < $height; $y++) {
$y_array = array() ;
for ($x = 0; $x < $width; $x++) {
$rgb = imagecolorat($image, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
$x_array = array($r, $g, $b) ;
$y_array[] = $x_array ;
}
$colors[] = $y_array ;
}
print_r($colors);
?>
Comments correct, added $r, $g, $b. Restructured #jari answer and now getting a good output.
Cheers!

Answer 2

function getArrayOfPixelsFromFile($source) {
$image = imagecreatefromjpeg($source); // imagecreatefromjpeg/png/
$width = imagesx($image);
$height = imagesy($image);
$colors = array();
for ($y = 0; $y < $height; $y++) {
$y_array = array();
for ($x = 0; $x < $width; $x++) {
//Seleciona a cor localizada em ($x, $y)
$rgb = imagecolorat($image, $x, $y);
//echo $rgb." = ".decbin($rgb),"<br>";
//Seleciona os primeiros dois bytes que representam vermelho
$r = ($rgb >> 16) & 0xFF;
//Seleciona os dois bytes do meio que representam o verde
$g = ($rgb >> 8) & 0xFF;
//Seleciona os dois últimos bytes que representam o azul
$b = $rgb & 0xFF;
$x_array = array($r, $g, $b);
$y_array[] = $x_array;
}
$colors[] = $y_array;
}
return $colors;
}

Answer 3

I fixed your code by creating subarrays and adding elements to it as it should be.
for ($y = 0; $y < $height; $y++)
{
$height_arr = array() ;
for ($x = 0; $x < $width; $x++)
{
$rgb = imagecolorat($image, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
$width_arr = array($r, $g, $b) ;
$height_array[] = $width_arr ;
}
$colors[] = $height_arr ;
}

Answer 4

How about this?
[...]
$colors = [];
for ($y = 0; $y < $height; $y++) {
for ($x = 0; $x < $width; $x++) {
$rgb = imagecolorat($image, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
$colors[$y][$x] = array($r,$g,$b); // or, $colors[$x][$y] = array($r,$g,$b);
}
}
print_r($colors);