使用 UIImageJPEGRepresentation 时，什么数字保留全分辨率？
When using UIImageJPEGRepresentation what number retains full resolution?
有人可以为我解释一下比例（0 到 1）吗？哪个最好 quality/least，这对文件大小有何影响？
关于规模
The quality of the resulting JPEG image, expressed as a value from 0.0 to 1.0. The value 0.0 represents the maximum compression (or lowest quality) while the value 1.0 represents the least compression (or best quality).
有人可以为我解释一下比例（0 到 1）吗？哪个最好 quality/least，这对文件大小有何影响？
关于规模
The quality of the resulting JPEG image, expressed as a value from 0.0 to 1.0. The value 0.0 represents the maximum compression (or lowest quality) while the value 1.0 represents the least compression (or best quality).