Tone mapping

About: Tone mapping is a research topic. Over the lifetime, 1713 publications have been published within this topic receiving 48490 citations.

Color Saturation Compensation in iCAM06 for High-Chroma HDR Imaging

Abstract: An image appearance model called iCAM06 was designed for high dynamic range (HDR) image rendering. The dynamic range of an HDR image needs to be mapped on output devices, which is called tone compression or tone mapping. The iCAM06, the representative HDR rendering algorithm, uses tone compression for image reproduction on the low dynamic range of output devices. However, color saturation reduction occurs during its tone compression process. We propose a saturation correction method using the inverse compensation in order to recover the saturation reduction in the iCAM06. Experimental results show that the proposed method has better performance than the iCAM06 from the viewpoint of saturation accuracy and rendering preference.

Method and device for tone-mapping a high dynamic range image

Abstract: The present invention generally relates to a method and device for tone-mapping an image. The method is characterized in that it comprises: obtaining (12) a residual image by dividing the image by a backlight image determined (11) from the image, and obtaining (13) a tone-mapped image by tone-mapping to the residual image.

Making HDR viewing a content owner agreed process

Abstract: To allowed for increased security for selling HDR movies (or at least HDR experiences) even when some of the movie data gets pirated, an image transformation apparatus (201) is arranged to derive a e.g. a high dynamic range image (HDR_PRED) from a low dynamic range image (LDR_CONT) or any dynamic range image (e.g. a display driving image) from any dynamic range input image, wherein the derivation comprises tone mapping of lumas of pixels in the low dynamic range image into lumas of pixels of the high dynamic range image by applying at least one predefined mapping algorithm (gam), the image transformation apparatus comprising: -an input (204) to a data delivery system (205) comprising the low dynamic range image; -a data-secured input (206) to the at least one predefined mapping algorithm (gam) data; and -a control unit (202) arranged to manage access to the predefined mapping algorithm data under control of an owner of artistic content in the low dynamic range image, which allows for better control of the authorized regularity of the content when it is to be rendered, which is possible because of our special HDR image encoding strategy.

Photography Enhancement Based on the Fusion of Tone and Color Mappings in Adaptive Local Region

Abstract: Existing tone reproduction schemes are generally based on a single image and are, therefore, unable to accurately recover the local details and colors of scene since the limited available information. Accordingly, the proposed tone reproduction system utilizes two images with different exposures (one low and one high) to capture the local detail and color information of low- and high-luminance regions of scene, respectively. The adaptive local region of each pixel is developed in order to appropriately reveal the details and maintain the overall impression of scene. Our system implements the local tone mapping and color mapping based on the adaptive local region by taking the lowly-exposed image as the basis and referencing the information of highly-exposed image. The local tone mapping compresses the luminance range in the image and enhances the local contrast to reveal the details, while the local color mapping maps the precise color information from the highly-exposed image to the lowly-exposed image. Finally, a fusion process is proposed to mix the local tone mapping and local color mapping results to produce the output image. A multiresolution approach is also developed to reduce time cost. The experimental results confirm that the system generates realistic reproductions of HDR scenes.

Interactive local tone mapping operator with the support of graphics hardware

Abstract: The flexibility of current graphics hardware is still not enough to ensure the full implementation of an original complex algorithm such as a local tone mapping operator, which maintains the same quality performances as its original CPU implementation. Significant changes are often needed to the original CPU implementation in order to overcome many of the limitations of the current graphics hardware. As a result of this we often have reduced quality reproduction, and the frame rate of the GPU implementation is not always acceptable for real-time applications. In this paper, we show how to change the CPU implementation of a state of the art local tone mapping operator for accelerating the computation process to real time frame rates. We also present a modification of the luminance local adaptation computation, showing a simple but not yet exploited property of the Gaussian filter, allowing us to maintain the same quality appearance of the original tone mapping operator. Finally we test the hardware implementation on NVIDIA graphics cards on several images and as well as a video. We compare our hardware implementation with the corresponding CPU implementation and previous work.