php - 创建图像而不将其存储为本地文件

Question

这是我的情况 - 我想从用户上传的图像创建一个调整大小的 jpeg 图像，然后将其发送到 S3 进行存储，但我希望避免将调整大小的 jpeg 写入磁盘，然后为 S3 请求重新加载它.

有没有办法完全在内存中完成此操作，并将图像数据 JPEG 格式保存在变量中？

Answer 1

大多数使用 PHP 的人都会选择 ImageMagick或Gd2

我从未使用过 Imagemagick； Gd2方法:

<?php

// assuming your uploaded file was 'userFileName'

if ( ! is_uploaded_file(validateFilePath($_FILES[$userFileName]['tmp_name'])) ) {
    trigger_error('not an uploaded file', E_USER_ERROR);
}
$srcImage = imagecreatefromjpeg( $_FILES[$userFileName]['tmp_name'] );

// Resize your image (copy from srcImage to dstImage)
imagecopyresampled($dstImage, $srcImage, 0, 0, 0, 0, RESIZED_IMAGE_WIDTH, RESIZED_IMAGE_HEIGHT, imagesx($srcImage), imagesy($srcImage));

// Storing your resized image in a variable
ob_start(); // start a new output buffer
  imagejpeg( $dstImage, NULL, JPEG_QUALITY);
  $resizedJpegData = ob_get_contents();
ob_end_clean(); // stop this output buffer

// free up unused memmory (if images are expected to be large)
unset($srcImage);
unset($dstImage);

// your resized jpeg data is now in $resizedJpegData
// Use your Undesigned method calls to store the data.

// (Many people want to send it as a Hex stream to the DB:)
$dbHandle->storeResizedImage( $resizedJpegData );
?>

希望这有帮助。