Imagick::annotateImage()

(PECL imagick 2.0.0)

Annotates an image with text

说明

Imagick::annotateImage(ImagickDraw$draw_settings,float $x,float $y,float $angle,string $text): bool

Annotates an image with text.

参数

$draw_settings: The ImagickDraw object that contains settings for drawing the text
$x: Horizontal offset in pixels to the left of text
$y: Vertical offset in pixels to the baseline of text
$angle: The angle at which to write the text
$text: The string to draw

返回值

成功时返回TRUE。

范例

Example #1 Using Imagick::annotateImage():

Annotate text on an empty image

<?php
/* Create some objects */
$image = new Imagick();
$draw = new ImagickDraw();
$pixel = new ImagickPixel( 'gray' );
/* New image */
$image->newImage(800, 75, $pixel);
/* Black text */
$draw->setFillColor('black');
/* Font properties */
$draw->setFont('Bookman-DemiItalic');
$draw->setFontSize( 30 );
/* Create text */
$image->annotateImage($draw, 10, 45, 0, 'The quick brown fox jumps over the lazy dog');
/* Give image a format */
$image->setImageFormat('png');
/* Output the image with headers */
header('Content-type: image/png');
echo $image;
?>

参见

ImagickDraw::annotation() Draws text on the image
ImagickDraw::setFont() Sets the fully-specified font to use when annotating with text

If ImagickDraw::setGravity ( int $gravity ) has been set, e,g; with $gravity= imagick::GRAVITY_CENTER.
Then, the x and y values offset the text from where the gravity setting would have placed it. 
If the example included: $draw->setGravity (Imagick::GRAVITY_CENTER);
$image->annotateImage($draw, 10, 45, 0, 'The quick brown fox jumps over the lazy dog');
The text would be rendered to the right 10px and down 45px from the center. 
Gravity constants are very useful as they can save having to calculate the placement of variable text strings and font sizes.

$image->annotateImage($draw, 10, 45, 0, 'The quick brown fox');
If the third parameter, the 'Y' value, is 0, the text will be invisible because the text is printed ABOVE the image - not on the image. 
The solution is to start, depending on your chosen font size, with a Y value of about 40 and experiment.
[Also:]
When wishing to print some text on a photograph and make that text sufficiently contrasting to the background image, use a 4 byte code for colour and transparency.
It is the same 4 byte code using by the parameter '-undercolor' in ImageMagick's command lime instruction 'convert'.
The first 3 bytes are the RGB colour code and the fourth byte is the transparency byte.
<?php
  $picin = new Imagick($pic1);
  $picin->scaleimage(800,0);
  $height = $picin->getimageheight();
  $draw = new ImagickDraw();
  $draw->setFillColor('#ffff00');
  $draw->setFont('Eurostile');
  $draw->setFontSize(21);
  $draw->setTextUnderColor('#ff000088');
  $picin->annotateImage($draw,40,$height-10,0,"Hallo");
  $picin->writeimage($pic6);
?>
The example code produces yellow text on a semi-transparent red background.
$pic1 and $pic6 were previously defined as directory/file strings.

Does not work with CMYK color values and images. Only RGB.