flutter_image_compress 的质量如何
What is the quality in flutter_image_compress
我发现 flutter_image_compress 的质量压缩不是基于百分比。例如，4.58MB 的图像在质量 50 压缩后是 return 590KB。那是不是说质量不是百分比？
参考：https://jtmuller5-98869.medium.com/image-compression-in-flutter-e0585ce960cc
quality 不是百分比。它被传递给底层的 JPEG 压缩器，因此您必须查看底层压缩器如何解释它。但即便如此，也可能没有很好的记录。
例如，在 iOS、the implementation divides quality by 100 to convert it to a number in the range 0.0 to 1.0 and uses the resulting fraction as the kCGImageDestinationLossyCompressionQuality 参数上。 Apple 将该参数记录如下：
The desired compression quality to use when writing to an image destination. If present, the value associated with this key must be a CFNumberRef data type in the range 0.0 to 1.0. A value of 1.0 specifies to use lossless compression if destination format supports it. A value of 0.0 implies to use maximum compression.
我发现 flutter_image_compress 的质量压缩不是基于百分比。例如，4.58MB 的图像在质量 50 压缩后是 return 590KB。那是不是说质量不是百分比？
参考：https://jtmuller5-98869.medium.com/image-compression-in-flutter-e0585ce960cc
quality 不是百分比。它被传递给底层的 JPEG 压缩器，因此您必须查看底层压缩器如何解释它。但即便如此，也可能没有很好的记录。
例如，在 iOS、the implementation divides quality by 100 to convert it to a number in the range 0.0 to 1.0 and uses the resulting fraction as the kCGImageDestinationLossyCompressionQuality 参数上。 Apple 将该参数记录如下：
The desired compression quality to use when writing to an image destination. If present, the value associated with this key must be a
CFNumberRefdata type in the range0.0to1.0. A value of1.0specifies to use lossless compression if destination format supports it. A value of0.0implies to use maximum compression.