Change the Brightness of the Picture

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Current Image:

Select Brightness ( 0 = No Change, 10 = Brightest)

Brightness Determination:

Bright

0   1   2   3   4   5  

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SLAVE CODE FOLLOWS <?php
$brightness = $_GET['br'];

$image = imagecreatefromjpeg("fluffycat.jpg");

imagetruecolortopalette($image, true, 256);

$totalColors = imagecolorstotal($image);

for ($index = 0; $index < $totalColors; $index++)
{
    // $RGB is an array
    $RGB = imagecolorsforindex($image, $index);
    $red = adjustBightness($RGB['red'], $brightness);
    $green = adjustBightness($RGB['green'], $brightness);
    $blue = adjustBightness($RGB['blue'], $brightness);
    imagecolorset($image, $index, $red, $green, $blue);
}
header("Content-type: image/jpeg");
imagejpeg($image);
imagedestroy($image);

function adjustBightness($color, $brightness)
{
    // determine the color brightness
    $color += (($brightness / 10) * 255);

    // make sure the color value does not exceed 255
    $color = ($color > 255) ? 255 : $color;
    return $color;
}

?>

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CODE FOLLOWS

<?php
include('includes/header.php');

$self = basename($_SERVER['SCRIPT_NAME']);
$step = isset($_POST['step']) ? $_POST['step'] : 1;
$brightness = isset($_POST['choice']) ? $_POST['choice'] : null;

$s = 'CHECKED';

if (isset($_POST['choice']))
{
    $choice = $_POST['choice'];
}
else
{
    $choice = 0;    // set default here
}
?>

<h1>
    Change the Brightness of the Picture
</h1>
<?php

switch ($step)
{

// STEP 1 ----------------------

case 1:    //--- get the change of brightness the user wants
?>
<hr>
<p>
    Current Image:
</p>
<img src="fluffycat.jpg" alt="Fluffy Cat">
<p>
    Select Brightness ( 0 = No Change, 10 = Brightest)
</p>
<form action="<?php echo($self); ?>" method="post">
    <fieldset>
        <legend>Brightness Determination:</legend>
        <label for="choice">Bright</label>
        <br><br>
        <?php
        for ($i = 0; $i <= 5; $i++)
        {
        ?>

        <input type="radio" id="choice" name="choice"
               value="<?php echo($i); ?>"<?php if ($choice == $i) {
            echo($s);
        } ?> > <?php echo($i); ?> &nbsp;
            <?php
        }
        ?>
    </fieldset>
    <br>
    <br>
    <input type="submit" name="submit" value="Submit">
    <input type="hidden" name="step" value="2">
</form>
<br>

<hr>
    <?php
    break;

// STEP 2 ----------------------

case 2:    //--- show the brightness

// provide the user the opportunity to try again
?>
<hr>

<h3> Brightness: <?php echo($brightness); ?></h3>

<img src="bright.php?br=<?php echo($brightness); ?> alt="My Bright Dog">

<br>

<form action="<?php echo($self); ?>" method="post">
    <input type="hidden" name="step" value="1">
    <input type="submit" value="Try Again">
</form>

<br>
        <?php
        break;
}
echo('<hr><br>SLAVE CODE FOLLOWS');
highlight_file('bright.php');
echo('<hr>');

include('includes/footer.php');
?>

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