Scale an image using the given new width and height

imagescale ( resource $image , int $new_width [, int $new_height = -1 [, int $mode = IMG_BILINEAR_FIXED ]] ) : resource

imagescale() scales an image using the given interpolation algorithm.

Note:
Unlike many of other image functions, imagescale() does not modify the passed image; instead, a new image is returned.

image

由图象创建函数(例如imagecreatetruecolor())返回的图象资源。

new_width

The width to scale the image to.

new_height

The height to scale the image to. If omitted or negative, the aspect ratio will be preserved.

mode

One of IMG_NEAREST_NEIGHBOUR, IMG_BILINEAR_FIXED, IMG_BICUBIC, IMG_BICUBIC_FIXED or anything else (will use two pass).

Note: IMG_WEIGHTED4 is not yet supported.

Return the scaled image resource on success 或者在失败时返回 FALSE.