[{"createTime":1735734952000,"id":1,"img":"hwy_ms_500_252.jpeg","link":"https://activity.huaweicloud.com/cps.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=V1g3MDY4NTY=&utm_medium=cps&utm_campaign=201905","name":"华为云秒杀","status":9,"txt":"华为云38元秒杀","type":1,"updateTime":1735747411000,"userId":3},{"createTime":1736173885000,"id":2,"img":"txy_480_300.png","link":"https://cloud.tencent.com/act/cps/redirect?redirect=1077&cps_key=edb15096bfff75effaaa8c8bb66138bd&from=console","name":"腾讯云秒杀","status":9,"txt":"腾讯云限量秒杀","type":1,"updateTime":1736173885000,"userId":3},{"createTime":1736177492000,"id":3,"img":"aly_251_140.png","link":"https://www.aliyun.com/minisite/goods?userCode=pwp8kmv3","memo":"","name":"阿里云","status":9,"txt":"阿里云2折起","type":1,"updateTime":1736177492000,"userId":3},{"createTime":1735660800000,"id":4,"img":"vultr_560_300.png","link":"https://www.vultr.com/?ref=9603742-8H","name":"Vultr","status":9,"txt":"Vultr送$100","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":5,"img":"jdy_663_320.jpg","link":"https://3.cn/2ay1-e5t","name":"京东云","status":9,"txt":"京东云特惠专区","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":6,"img":"new_ads.png","link":"https://www.iodraw.com/ads","name":"发布广告","status":9,"txt":"发布广告","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":7,"img":"yun_910_50.png","link":"https://activity.huaweicloud.com/discount_area_v5/index.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=aXhpYW95YW5nOA===&utm_medium=cps&utm_campaign=201905","name":"底部","status":9,"txt":"高性能云服务器2折起","type":2,"updateTime":1735660800000,"userId":3}]
在描述一个场景的时候,动态范围(Dynamic Range)指的是其最亮部与最暗部的亮度比值。高动态范围的场景(High Dynamic
Range Scene)指的是场景里同时存在非常明亮和非常暗淡的部分。
图像传感器所能捕捉的动态范围是有限的,它受到两个因素的限制,一个是满阱容量(Full Well
Capacity,FWC),另一个则是它的本底噪声。
* 满阱容量越大,CMOS
就越不容易饱和。如果场景里明亮的部分释放出太多光子,那么图像传感器就会饱和,超出这个容量的光子无法被捕捉,这些高光信息也就无法被保存下来。
* 类似地,对于太过暗淡的部分,那些光子的信号强度不够,那么就会淹没在图像传感器的噪声(Noise Floor)中,无法被记录下来。
要想在一张照片里记录尽可能多的明暗细节,就需要尽可能扩大传感器的
FWC,并尽可能地抑制其本底噪声,然而,受制于使用场景所能容纳的传感器尺寸,以及当前可用的技术,传感器能获得的提升是有限的。
因此,工程师们另辟蹊径,通过其他的方法来捕捉这种高动态范围的场景,这就是高动态范围成像技术(HDR Imaging)。