PHP GD Functions

The rotation $angle is interpreted as the number of degrees to rotate the image anticlockwise.

The $background_color specifies the color of the uncovered zone after the rotation.

If $ignore_transparent = 0 transparent colors are ignored, otherwise kept.

This function is affected by the interpolation method set by imagesetinterpolation and will be seen on the next page.

This function returns FALSE on failure.


<?php

GdImage|false imagerotate (  GdImage $image,
                                                     float $angle,
                                                        int $background_color,
                                                     bool $ignore_transparent = false )


where,

$image = The image identifier

$angle = The rotation angle in degrees 

$background_color = The color of the uncovered zone 
                                                after the rotation 

$ignore_transparent = To control the transparent colors
                                        This parameter is unused

?>

$image

The image identifier.

$angle

The rotation angle in degrees.

$background_color

The color of the uncovered zone after the rotation.

$ignore_transparent

To control the transparent colors.

EXERCISE


<?php

echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';

$tst_img = "gif/GIF 020 01.gif"; // 256 colors
$dst1_img = "gif/GIF 020 01(90 degrees).gif";
$dst2_img = "gif/GIF 020 01(10 degrees).gif";
$dst3_img = "gif/GIF 020 01(-10 degrees).gif";

echo $tst_img; ?>
<br><br><img src="<?php echo  $tst_img; ?>" 
alt="<?php echo $tst_img; ?>"><br><br><br><br>

<?php
$id_org = imagecreatefromgif( $tst_img);
$ang_r1 = 90;
$ang_r2 = 10;
$ang_r3 = -10;
$bkg_2 = 0xeeeeee;
// background color
$bkg_3 = 0xeeeeee;
// background color
$trn = 100;
// this parameter is unused

$id_dst1 = imagerotate($id_org, $ang_r1, NULL, $trn );
imagegif ($id_dst1,  $dst1_img);

$id_dst2 = imagerotate($id_org, $ang_r2, $bkg_2, $trn );
imagegif ($id_dst2,  $dst2_img);

$id_dst3 = imagerotate($id_org, $ang_r3, $bkg_3, $trn );
imagegif ($id_dst3,  $dst3_img);

echo $dst1_img; ?>
<br><br><img src="<?php echo  
$dst1_img; ?>" alt="<?php echo $dst1_img; ?>"><br><br>


<?php echo $dst2_img; ?>
<br><br><img src="<?php echo  
$dst2_img; ?>" alt="<?php echo $dst2_img; ?>"><br><br>

<?php echo $dst3_img; ?>
<br><br><img src="<?php echo  
$dst3_img; ?>" alt="<?php echo $dst3_img; ?>"><br>

RESULT

GIF 020 01.gif

Existing Image

GIF 020 01.gif apr

GIF 020 01(90 degrees).gif

( 90° )

GIF 020 01(90 degrees).gif apr

GIF 020 01(10 degrees).gif

( 10° )

GIF 020 01(10 degrees).gif apr

GIF 020 01(-10 degrees).gif

( -10° )

GIF 020 01(-10 degrees).gif apr

EXERCISE


<?php

echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';

$tst_img = "jpeg/JPEG 025 01.jpg"; // TRUECOLOR
$dst1_img = "jpeg/JPEG 025 01(90 degrees).jpg";
$dst2_img = "jpeg/JPEG 025 01(10 degrees).jpg";
$dst3_img = "jpeg/JPEG 025 01(-10 degrees).jpg";

echo $tst_img; ?>
<br><br><img src="<?php echo  $tst_img; ?>" 
alt="<?php echo $tst_img; ?>" width="400"><br><br><br><br>

<?php
$id_org = imagecreatefromjpeg( $tst_img);
$ang_r1 = 90;
$ang_r2 = 10;
$ang_r3 = -10;
$bkg_2 = 0xeeeeee;    // background color
$bkg_3 = 0xeeeeee;   // background color
$trn = 0;                // this parameter is unused

$id_dst1 = imagerotate($id_org, $ang_r1, NULL, $trn );
imagejpeg ($id_dst1,  $dst1_img);

$id_dst2 = imagerotate($id_org, $ang_r2, $bkg_2, $trn );
imagejpeg ($id_dst2,  $dst2_img);

$id_dst3 = imagerotate($id_org, $ang_r3, $bkg_3, $trn );
imagejpeg ($id_dst3,  $dst3_img);

echo $dst1_img; ?>
<br><br><img src="<?php echo  
$dst1_img; ?>" alt="<?php echo $dst1_img; ?>" width="400"><br><br>


<?php echo $dst2_img; ?>
<br><br><img src="<?php echo  
$dst2_img; ?>" alt="<?php echo $dst2_img; ?>" width="400"><br><br>

<?php echo $dst3_img; ?>
<br><br><img src="<?php echo  
$dst3_img; ?>" alt="<?php echo $dst3_img; ?>" width="400"><br>