照片尺寸和用户相册的转换？

Question

是否有任何php库可用于将照片重新缩放或重新调整为我们为高度/宽度/大小设置的限制，如果用户将照片上传为gif png或bmp然后将其转换为jpeg？

Answer 1

Are there any php libraries for this to re-scale or re-size photos down to whatever limit we set for height/width/size and also if users upload photos in gif png, or bmp then convert them to jpeg?

GD and ImageMagick

(I'm ignoring the rest of your questions as they aren't programming related. I suggest you edit and remove those sections.)

Answer 2

What aspect ratio and file sizes to use are largely subjective, but there are a few guidelines you may want to follow.

For aspect ratio the best thing to do (photographically at least) is to keep the same aspect as the original. I'd avoid stretching the photo in any way. If you have to, maybe crop it to fit a certain aspect ratio.

For file size, it really depends on what you want to do. Make them larger if you really want to retain a lot of quality and resolution.

There are many libraries available for image editing in PHP. I typically use GD. http://ca3.php.net/manual/en/refs.utilspec.image.php