php复制图像增加文件大小

Question

I am using php to resize and crop images. However the cropped image file is greater than ( much greater in some cases) than the original file. I even tried without cropping (copying the original image) but the resulting size is more than the original image.

$ImageName = '/IMAGES/testImage.jpg';

//Download the Image File

$base_url = 'https://image.jimcdn.com/app/cms/image/transf/none/path/sa6549607c78f5c11/image/ia62ed3191fcc424f/version/1457278719/athens-european-best-destinations.jpg';
$image_size = getimagesize($base_url);
$image_width =  $image_size[0];
$image_height =  $image_size[1];

$src_image = imagecreatefromjpeg($base_url);

//Copy Image Object To File 
imagejpeg($src_image, $ImageName, 100);

Answer 1

Technically, the quality rate of the conversion is not derivable from the jpeg data, it just tells the converter which tradeoff to make between size and quality.

Some converters store it in the EXIF data of the JPEG header though, so if that is still present you can use it with exif_read_data on it, and see if the compression information is returned.

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