Scale an image using the given new width and height

imagescale(
    GdImage $image,
    int $width,
    int $height = -1,
    int $mode = IMG_BILINEAR_FIXED
): GdImage|false

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

注意:
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 GdImage 对象。

width

The width to scale the image to.

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).

注意: IMG_WEIGHTED4 is not yet supported.

Return the scaled image object on success 或者在失败时返回 false.

Throws a ValueError if width or height would cause over-/underflow.

Throws a ValueError if mode is invalid.

版本	说明
8.4.0	Now throws a ValueError if `width` or `height` would cause over-/underflow.
8.4.0	Now throws a ValueError if `mode` is invalid.
8.0.0	On success, this function returns a GDImage instance now; previously, a resource was returned.
8.0.0	`image` 现在需要 GdImage 实例；之前需要有效的 `gd` resource。