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php实现切图

2026-02-16 17:44:27PHP

PHP实现图片切割的方法

使用PHP的GD库或Imagick扩展可以实现图片切割功能。以下是两种常见的实现方式：

GD库实现图片切割

GD库是PHP内置的图像处理库，适合基础图片切割需求：

$srcImage = imagecreatefromjpeg('input.jpg');
$width = imagesx($srcImage);
$height = imagesy($srcImage);

// 定义切割参数
$tileWidth = 200;
$tileHeight = 200;

for ($y = 0; $y < $height; $y += $tileHeight) {
    for ($x = 0; $x < $width; $x += $tileWidth) {
        $tile = imagecreatetruecolor($tileWidth, $tileHeight);
        imagecopy($tile, $srcImage, 0, 0, $x, $y, $tileWidth, $tileHeight);
        imagejpeg($tile, "tile_{$x}_{$y}.jpg");
        imagedestroy($tile);
    }
}
imagedestroy($srcImage);

Imagick扩展实现图片切割

Imagick提供了更强大的图像处理能力：

$image = new Imagick('input.jpg');
$width = $image->getImageWidth();
$height = $image->getImageHeight();

$tileWidth = 200;
$tileHeight = 200;

for ($y = 0; $y < $height; $y += $tileHeight) {
    for ($x = 0; $x < $width; $x += $tileWidth) {
        $tile = clone $image;
        $tile->cropImage($tileWidth, $tileHeight, $x, $y);
        $tile->writeImage("tile_{$x}_{$y}.jpg");
        $tile->clear();
    }
}
$image->clear();

按比例切割图片

如果需要按比例切割图片，可以先计算实际像素值：

$image = imagecreatefromjpeg('input.jpg');
$width = imagesx($image);
$height = imagesy($image);

// 按3:2比例切割
$ratioW = 3;
$ratioH = 2;
$tileWidth = $width / $ratioW;
$tileHeight = $height / $ratioH;

// 切割逻辑与前面相同

保存透明PNG图片

处理透明图片时需要特别注意：

$image = imagecreatefrompng('input.png');
imagealphablending($image, false);
imagesavealpha($image, true);

// 切割逻辑
$tile = imagecreatetruecolor($tileWidth, $tileHeight);
imagealphablending($tile, false);
imagesavealpha($tile, true);
$transparent = imagecolorallocatealpha($tile, 0, 0, 0, 127);
imagefill($tile, 0, 0, $transparent);

// 保存为PNG
imagepng($tile, "output.png");