Camera (CamCyclopedia)
1. Definition of HDR
HDR stands for High Dynamic Range and is a technology that expands the range of brightness and color expression of images compared to existing SDR, creating or reproducing vivid images that are closer to what the human eye perceives.
This HDR technology preserves a wide range of brightness within an image, from the intense light of the sun to the starlight in the darkest night sky, and creates a realistic feel by utilizing the widest range of color expressions perceptible to humans.
HDR mainly uses 10 bits or more of data to produce smoother color shifts. Simply put, it allows for natural expressions in expressing more or less red.
The overall steps from creation to transmission and display of HDR images are as follows.
In order to capture an image as photorealistic as possible, a good sensor is used to obtain images with a wider color gamut, deeper color depth, and greater contrast ratio, and then the optimal HDR image is created through the mastering stage, which is then produced and transmitted as a compressed file.
The transmitted HDR image is finally then displayed through tone mapping and color conversion technology to match the user's display specifications.
2. Types of HDR
The different types of HDR are HLG, HDR10, HDR10+, and Dolby vision and the Samsung Galaxy S25 currently supports dual HLG, HDR10, and HDR10+ based on rendering.
The biggest difference between each HDR is the gamma related to the brightness of the image data used, and the type of additional meta information for interpreting the HDR image.
| HDR Type | Gamma | Meta information |
| HLG | HLG | None |
| HDR10 | PQ | Static metadata |
| HDR10+ | PQ | Dynamic metadata |
| Dolby vision | HLG/PQ | Dynamic metadata |
These differences cause each HDR type to be interpreted differently.
Currently, Netflix mainly provides HDR services in HDR10 and Dolby vision, while Amazon provides it in HDR10+ and HDR10, and HDR videos created on iPhones are in Dolby vision.
3. 10bit HDR in Galaxy S25
One of the biggest changes to the Galaxy S25's 10-bit HDR is HDR recording.
Until now, the default had been SDR recording, but from Galaxy S25, HDR recording is the default.
The HDR used in HDR default recording is HLG, which stands for Hybrid Log Gamma and is an HDR Video developed by BBC and NHK, characterized by the absence of additional meta information within the video content.
Even without additional meta information, HLG's own tone mapping allows interpretation according to display brightness, and above all, it has excellent compatibility as it has many overlapping sections with the existing SDR gamma, and these characteristics provide a great advantage when sharing videos while maintaining HDR image quality.
For example, even if the device that receives the HDR video does not have the function to process HDR, the video can still be viewed without color fading or saturation, although the image quality will not be as good as HDR.
When it comes to the production of professional content, such as HDR films, it is produced by going through a precise mastering stage using expensive equipment in specialized studios.
At this stage, the film director is often directly involved in matters such as the producer's color, brightness, etc., and the HDR image quality can also be affected depending on how much effort the director, colorist, and HDR expert put into mastering to accurately reflect the producer's intention.
In the Galaxy S25, we have tried to automate and streamline these professional mastering steps on smartphones to create the best possible image quality, not just for recording, but also for the final display quality by optimizing the quality of the rendering technology.
※ It is not supported on models that have already been released as this function requires some hardware support and is not supported by OS updates.
