公开(公告)号：US09635212B2

公开(公告)日：2017-04-25

申请号：US14502629

申请日：2014-09-30

Applicant: Apple Inc.

Inventor： Anders Holtsberg ,  Brandon Corey ,  Martin Lindberg

IPC: H04N1/21 ,  H04N5/232 ,  H04N19/172 ,  H04N19/46 ,  H04N19/115 ,  H04N19/17 ,  H04N19/154 ,  H04N19/436 ,  H04N19/134

CPC classification number: H04N1/2112 ,  H04N5/23229 ,  H04N19/115 ,  H04N19/134 ,  H04N19/154 ,  H04N19/17 ,  H04N19/172 ,  H04N19/436 ,  H04N19/46

Abstract: An image is compressed according to a compression ratio selected based on a compression metric. In one embodiment, the compression metric is based on image characteristics indicative of the amount of image noise in an image, such as gain and lux. Greater compression ratios are used for image having compression metrics indicating a higher degree of noise. Because an image with higher image noise levels already has a reduced visual quality, the impact of higher compression is less significant as compared to the impact of compression on images having low image noise. In an embodiment, an image is divided into a number of regions, for each of which a compression metric and corresponding compression ratio is determined, so that regions of the image having high image noise may be compressed more than regions having low image noise.

公开(公告)号：US20150350483A1

公开(公告)日：2015-12-03

申请号：US14502629

申请日：2014-09-30

Applicant: Apple Inc.

Inventor： Anders Holtsberg ,  Brandon Corey ,  Martin Lindberg

IPC: H04N1/21 ,  H04N5/232

CPC classification number: H04N1/2112 ,  H04N5/23229 ,  H04N19/115 ,  H04N19/134 ,  H04N19/154 ,  H04N19/17 ,  H04N19/172 ,  H04N19/436 ,  H04N19/46

Abstract: An image is compressed according to a compression ratio selected based on a compression metric. In one embodiment, the compression metric is based on image characteristics indicative of the amount of image noise in an image, such as gain and lux. Greater compression ratios are used for image having compression metrics indicating a higher degree of noise. Because an image with higher image noise levels already has a reduced visual quality, the impact of higher compression is less significant as compared to the impact of compression on images having low image noise. In an embodiment, an image is divided into a number of regions, for each of which a compression metric and corresponding compression ratio is determined, so that regions of the image having high image noise may be compressed more than regions having low image noise.

Abstract translation: 根据基于压缩度量选择的压缩比来压缩图像。 在一个实施例中，压缩度量基于指示图像中的图像噪声量的图像特性，例如增益和勒克斯。 对于具有指示较高噪声程度的压缩度量的图像，使用更大的压缩比。 由于具有较高图像噪声水平的图像已经具有降低的视觉质量，与压缩对具有低图像噪声的图像的影响相比，较高压缩的影响不太显着。 在一个实施例中，图像被分成多个区域，对于每个区域，确定压缩度量和对应的压缩比，使得具有高图像噪声的图像的区域可以被压缩得比具有低图像噪声的区域多。