A sample to view Display P3 images on Android devices. If Android OS and device both support display P3 mode, two versions of the image will be displayed:
- Display P3 view on the left hand side
- sRGB view on the right hand side
- Android Oreo (API level >= 26) device that supports wide color gamut mode (Implemented on Android Oreo with Display P3 color space)
- Android Studio 3.5.2+
- Android NDK-r20+
- Enable "Natural" mode for "Color" configuration: Settings > Display > Colors
- Download Android Studio
- Download Android NDK-r15+
- Download source code
- Launch Android Studio.
- "File"-->"New" --> "Import Project", select display-p3/build.gradle
- "Run" --> "Run 'app'"
This sample creates Display P3 EGLContext_, then creates 2 textures for each PNG file under "assets" folder, and on Android devices support Display P3:
- the first is in Display P3 image mode,
- the second is in sRGB mode. The sRGB texture is created by transforming the original Display P3 image into CIExyz 1931 color space, clamping colors in sRGB color space, then transforming it back to Display P3 color space to display.
For Android Devices that does NOT support display P3, both textures will be in sRGB (identical view)
The Display P3 mode is turned on when application requests a window surface of type
EGL_GL_COLORSPACE_DISPLAY_P3_EXT:
std::vector<EGLint> attributes;
attributes.push_back(EGL_GL_COLORSPACE_KHR);
attributes.push_back(EGL_GL_COLORSPACE_DISPLAY_P3_EXT);
attributes.push_back(EGL_NONE);
engine->surface_ = eglCreateWindowSurface(
engine->display_, config, engine->app->window, attributes.data());Android 10+ supports EGL_GL_COLORSPACE_DISPLAY_P3_PASSTHROUGH_EXT, the sample detects the extension and enables it instead of EGL_GL_COLORSPACE_DISPLAY_P3_EXT. The difference between the two is on how to handle OETF/EOTF ( gamma like thing):
- EGL_GL_COLORSPACE_DISPLAY_P3_PASSTHROUGH_EXT tells hardware to bypass OETF/EOTF transfer functions
- EGL_GL_COLORSPACE_DISPLAY_P3_EXT enables transfer functions when writing to framebuffers. Note that the implementation on Android 8 and Android 9 for EGL_GL_COLORSPACE_DISPLAY_P3_EXT may varies on your test devices, if you see the color washing out or too dark, you could change the code to alter OETF/EOTF functionality and texture's setting to get a correct setting fit your system.
All images under the assets folder are assumed to be already encoded in Display P3 color space:
- gamma value : 2.2
- Display P3 color space with D65 as white reference point
To add new images, simply drop the new file into this folder. Please note that all decompressing is performed on CPU at the start up time: it takes time when there are lot of image files.
Some of the images are from codelogic's wide-gamut-tests repo. On Display P3 capable devices, details inside red and green areas are noticeably different, blue area is almost the same, just as expected.
Changing display mode:
- Tap on image to show/hide (Display P3 mode or sRGB mode)
- Swipe up/down to rotate through image files
More About Wide Color Gamut
- Color Management in Android Oreo
- Understanding Color (talk at Google I/O 2017)
- Enhancing Graphics with Wide Color Content
| Version | Date | Note |
|---|---|---|
| 1.0 | 07/2017 | Initial Version |
| --------- | -------- | -------------------------------- |
| 1.1 | 12/2019 | Added P3_PASSTHROUGH_EXT |
If you've found an error in these samples, please file an issue.
Patches are encouraged, and may be submitted by forking this project and submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details.
Copyright 2017 Google, Inc.
Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.