PHP Load Image imagecreatefrom_gif_jpeg_png series function usage Analysis _php skills

This paper analyzes the Imagecreatefrom_gif_jpeg_png series function usage of PHP loading image. Share to everyone for your reference, specific as follows:

The Imagecreatefrom series function is used to load an image from a file or URL.

Loading images

The Imagecreatefrom series function is used to load an image from a file or URL, return an image resource successfully, and return an empty string if it fails.

The series functions are:

Imagecreatefromgif (): Creates a canvas and loads an image from a GIF file or URL address
Imagecreatefromjpeg (): Creates a canvas and loads an image from a JPEG file or URL address
Imagecreatefrompng (): Creates a canvas and loads an image from a PNG file or URL address
Imagecreatefromwbmp (): Creates a canvas and loads an image from a WBMP file or URL address
Imagecreatefromstring (): Creates a canvas, and creates a new image from the image stream in the string

Grammar:

Resource Imagecreatefromgif (string filename)
resource imagecreatefromjpeg (string filename)
Resource Imagecreatefrompng (string filename)
resource imagecreatefromwbmp (string filename)
Resource Imagecreatefromstring (string image)

Example:

?
Header ("Content-type:image/jpeg");
Create and load a picture
$im = @imagecreatefromjpeg ("images/flower_1.jpg");
Error handling
if (! $im) {
  $im = Imagecreatetruecolor (from);
  $BG = Imagecolorallocate ($im, 255, 255, 255);
  $text _color = imagecolorallocate ($im, 0, 0, 255);
  Fill background color
  imagefilledrectangle ($im, 0, 0, $BG);
  Output error messages in Images
  imagestring ($im, 3, 5, 5, "Error loading image", $text _color);
  Imagejpeg ($im);
>

In this example, we load and output the original image. Because PHP does not have friendly error prompts for image creation errors, we have customized error handling information.

Tips

For PHP-generated images, if you want to display them directly in the normal Web page rather than through the header output, you can invoke the following:

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I hope this article will help you with the PHP program design.