Multi-Scale Tone Mapping

• Main Authors: BAI YINGJUN, ZHANG XUEMEI
• Format: Patent
• Language: English
• Published: 10.03.2016
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; HANDLING RECORD CARRIERS; PHYSICS; PRESENTATION OF DATA; RECOGNITION OF DATA; RECORD CARRIERS

Methods, devices and computer readable instructions to generate multi-scale tone curves are disclosed. One method includes finding, for a given input image, a global tone curve that exhibits monotonic behavior. The input image may then be partitioned into a first number of sub-regions. For each sub-region, a local tone curve may be determined that has an output level that is constrained to the global tone curve at one or more first luminance levels so that each sub-region's local tone curve's output follows the global tone curve's monotonic behavior. If the resulting local tone curves provide sufficient control of shadow-boost, highlight-suppression, and contrast optimization the first number of local tone curves may be applied directly to the input image. If additional control is needed, each sub-region may again be partitioned and local tone curves determined for each of the new sub-regions.