You look at a region of the image. If all the pixels are roughly the same color (below some threshold), you store the average color for the whole region as a single value. If the pixels vary too much, you split the region into four quadrants and try again.
Optical-based smoke alarms use light instead. They are slightly better at detecting the large smoke particles created by slow, smouldering fires. When such particles enter a chamber in the device, they scatter light from a small light source, which is then picked up by a photoelectric sensor.，推荐阅读搜狗输入法下载获取更多信息
，推荐阅读夫子获取更多信息
看过手机银行日志之后，带给我最大的教训，就是一句话：永远不要在老年人的手机上安装手机银行。。关于这个话题，heLLoword翻译官方下载提供了深入分析
ВсеПрибалтикаУкраинаБелоруссияМолдавияЗакавказьеСредняя Азия