4 results about "Inverse tone mapping" patented technology

The invention provides a method for inverse tone mapping, the method being performed by: obtaining (42) a gain function of a first inverse tone mapping function, referred to as an initial gain function; if (43) an analysis of a current image shows that at least one pixel of the current image having a luminance value at least equal to a predetermined percentage of luminance values (TH1) of the pixels of the current image has an expanded luminance value resulting from the application of the first ITM function to the current image which is higher than a target value, applying (45) to the current image a second ITM function, the second ITM function corresponding to the first inverse tone mapping function in which the gain function has been replaced by a modified gain function derived from the initial gain function in which the gain provided by the initial gain function is attenuated by an attenuation function, the attenuation function being weighted by a weighting factor controlling the intensity of the attenuation, the weighting factor depending on a statistical distribution of luminance values between the maximum luminance value in a histogram of the current image and the luminance value depending on the predetermined percentage.

This disclosure provides a method for inverse tone mapping, the method comprising: obtaining (41) a histogram of a low dynamic range image, referred to as an LDR image; obtaining (42) an ITMO function, thereby allowing pixel values ​​of a high dynamic range image, referred to as an HDR image, to be obtained from pixel values ​​of the LDR image and a gain function dependent on the pixel values ​​of the LDR image; applying a search process using the obtained histogram to identify regions of the LDR image that produce bright areas in the HDR image when the ITMO function is applied to the LDR image, thereby using information representing the bright areas to determine when to modify the gain function to ensure that the HDR image complies with at least one predefined light energy constraint.

This invention discloses a method, apparatus, and device for generating halo effects on a mobile device, comprising: acquiring an original image and extracting highlight regions from the original image to obtain highlight image attachments; performing inverse tone mapping on the highlight image attachments to obtain high dynamic range (HDR) brightened image attachments; performing multiple downsampling on the brightened image attachments to generate multiple downsampled image attachments with different resolutions; performing blurring processing on the brightened image attachments and each downsampled image attachment to obtain corresponding multiple blurred image attachments; upsampling and superimposing each blurred image attachment to generate a HDR halo composite attachment; performing tone mapping processing on the halo composite attachment to obtain a standard dynamic range (SDR) standard halo attachment; and superimposing the standard halo attachment with the original image based on the highlight image attachment to obtain the halo result image. This method can balance the visual realism of the halo effect with real-time processing performance under limited computing power.