These three functions have 3 parameters. The first parameter is the image stream, the second parameter is the saved file name, and the third parameter specifies the image quality.
Note that the third parameter is very important, it determines the quality and size of the image you regenerate. Imagejpeg and imagegif, the range of this parameter is 1-100, the default is 100, the larger the value, the higher the image quality; imagepng is 1-9, the default is the largest.
The above introduces the detailed explanation of the parameters of the PHP functions imagejpeg, imagepng, and imagegif, including the content of image and jpeg. I hope it will be helpful to friends who are interested in PHP tutorials.