Home How to Calibrate HDR Brightness to Avoid Distortion

How to Calibrate HDR Brightness to Avoid Distortion

Home How to Calibrate HDR Brightness to Avoid Distortion

How to Calibrate HDR Brightness to Avoid Distortion

by ruby

Issued Date: 2017/6/8
Issued By: iST

HDR (High Dynamic Range) has become the standard of television specifications.
As an engineer of display products, why discontinuous contour symptoms still happen even though you have followed the standard?
Either EOTF setup or IC design is wrong? How to calibrate?

More or less you may run into above problems. Aiming to present the real world in the eyes of consumers, High Dynamic Range (HDR) has become the hottest subject of imaging technology.

The biggest issue for most display engineers is how to ensure a real HDR image reproduction with the display product through the accurate process.

Although we know the CMOS and CCD Sensor can also deal with the HDR brightness images, it may still have trouble in the discontinuous brightness through the transportation from images to display. To solve the bottlenecks on your display development, iST has built the HDR Calibration and measurement services this year, for assisting HDR algorithm requirements and customized calibration, as well as in the role of consultant for getting certification.

See how iST is calibrating HDR images for well-known display manufacturers!

  • Case 1: Despite successfully calibrating according to the EOTF standard (The EOTF standard is aimed at the electro-optical conversion functions for converting telecommunications signals into visible light), the discontinuous contour is still obvious at high brightness.

    Discontinuous-contour-is-obvious-at-high-brightness-due-to-incorrect-algorithm.

    Discontinuous contour is obvious at high brightness due to incorrect algorithm.

    With-iST-tone-improvement-the-high-bright-region-becomes-smooth-and-keeps-the-contrast

    With iST’s tone improvement, the high bright region becomes smooth and keeps the contrast.


  • Case2: Discontinuous contour is obvious at high brightness due to excessive curve slope

    Poor contour on high bright region.

    Poor contour on high bright region.

    iST-tone-improvement

    iST’s tone improvement makes image with more steps in brightness and smother transitions, also keeps the original contrast.

  • Case 3: Poor contour on Dark region

    HDR Calibration on dark region is also a frequent challenge, which mainly results from the IC design. The chip increment value at low level should take into account; moreover, the chip should perform an ideal curve according to the theoretical value.

    Poor-contour-on-Dark-region

    Incorrect algorithm results in discontinuous contour in dark region.

    HDR-calibration

    iST’s calibration solves the discontinuous contour.

  • Case 4: Error occurs during measurement

    How to solve the errors to correct the EOTF and tone measurement is the key to overall performance.

    The-EOTF-measurement-before-correction

    The EOTF measurement before correction

    The-EOTF-measurement-after-correction

    The EOTF measurement after correction

We are more than glad to share our HDR Calibration experiences with you. In case of any further inquiries, please call Mr. Yu at +886-3-579-9909 Ext. 2682 or send him an email at si@istgroup.com.

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