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  • Imagick::rotateImage()

    (PECL imagick 2.0.0)

    Rotates an image

    说明

    Imagick::rotateImage(mixed $background,float $degrees): bool

    Rotates an image the specified number of degrees. Empty triangles left over from rotating the image are filled with the background color.

    参数

    $background

    The background color

    $degrees

    Rotation angle, in degrees. The rotation angle is interpreted as the number of degrees to rotate the image clockwise.

    返回值

    成功时返回TRUE

    更新日志

    版本说明
    2.1.0 Now allows a string representing the color as the first parameter. Previous versions allow only an ImagickPixel object.

    范例

    Example #1 Imagick::rotateImage()

    <?php
    function rotateImage($imagePath, $angle, $color) {
        $imagick = new \Imagick(realpath($imagePath));
        $imagick->rotateimage($color, $angle);
        header("Content-Type: image/jpg");
        echo $imagick->getImageBlob();
    }
    ?>
    
    Some transformations including Imagick ::rotateImage() may change "image page" -- working area inside the image you work on.
    Be careful with future modifications afterwards because the image page would be different from new sizes of the image.
    For example, if you do Imagic::cropImage() after rotation, you need to set image page properly, otherwise your crop would be performed relating to wrong coordinates (depending on rotation angle, resulting image size may vary).
    <?php
    $Image = new Imagick($sourceImagePath);
    $transparent = '#00000000';
    $Image->rotateImage(new \ImagickPixel(), 45); // This makes resulting image bigger
    // Set page to be of the full size of new image, starting at top left corner (0, 0)
    $Image->setImagePage($Image->getImageWidth(), $Image->getImageHeight(), 0, 0);
    $Image->cropImage($crop_w, $crop_h, $crop_x, $crop_y);
    ?>
    
    The degrees for imagick and gd is difference!
    GD > rotate 90 means counter clockwise.
    Imagick > rotate 90 means clockwise.
    GD 90 = Imagick 270 or Imagick 90 = GD 270.
    Use this function.
    <?php
    function calculateCounterClockwise($value)
    {
      if ($value == 0 || $value == 180) {
        return $value;
      }
      if ($value < 0 || $value > 360) {
        $value = 90;
      }
      $total_degree = 360;
      $output = intval($total_degree-$value);
      return $output;
    }// calculateCounterClockwise
    echo '1 = '.calculateCounterClockwise(1).'<br>';
    echo '90 = '.calculateCounterClockwise(90).'<br>';
    echo '270 = '.calculateCounterClockwise(270).'<br>';
    echo '359 = '.calculateCounterClockwise(359).'<br>';
    echo '360 = '.calculateCounterClockwise(360).'<br>';
    ?>
    test results:
    1 = 359
    90 = 270
    270 = 90
    359 = 1
    360 = 0
    Transparent 
    <?php $im->rotateImage(new ImagickPixel('#00000000'), 75); ?>
    
    If you want to rotate an image by a certain degree you can do this:
    <?php
    header('content-type: image/jpeg');
    $imagick = new Imagick();
    $imagick->readImage('castle.jpg');
    $imagick->rotateImage(new ImagickPixel(), 90);
    print $imagick->getImage();
    ?>
    
    You can rotate an jpg image by -13.55° into a transparent png image with :
    <?php
    $imagick = new Imagick(); 
    $imagick->readImage('my.jpg'); 
    $imagick->rotateImage(new ImagickPixel('none'), -13.55); 
    $imagick->writeImage('my_rotated.png');
    $imagick->clear();
    $imagick->destroy();
    ?>