GD for PHP

gd image processing technology

extension=php_gd2.dll

Create canvas

Canvas, a resource type data, operable image resource

• Create canvas (new)
  imageCreate(width,height) creates a palette-based canvas
  imageCreateTrueColor(width,height) Create a true color canvas
• Create a canvas based on a picture (open)
  imageCreateFromJPEG(url)
  imageCreateFromPNG(url)
  imageCreateFromGIF(url)

Operation canvas

Assign color: If you need to use a certain color on the canvas, you should assign the color to the canvas first.
(color identification) = imageColorAllocate(img,r,g,b)

fill canvas

imageFill(img,x,y,color identification)

output canvas

1, output to image file
2. For direct output, you need to tell the browser to output image information (header("Content-type:image/png;"))
imagePNG(img[,url])
imageJPEG()
imageGIF()

Destroy canvas resources

imageDestroy(img)

 header('content-type:image/png'); $img = imagecreate(300,300); $color = imagecolorallocate($img,223,22,44); imagefill($img,3,3,$color); imagepng($img); imagedestroy(); ?>

The above has introduced the GD of PHP, including various aspects. I hope it will be helpful to friends who are interested in PHP tutorials.