Bright

Description

Bright provides an easy way to determine if a background color is light or dark in order to choose an appropriate text color (black on light colors and white on dark colors) or to convert an image to grayscale. To do so, it calculates the luminance of a color from its rgb value or the luminance of an area (bitmap) from its average color.

The library is configurable through two variants:

• RELATIVE: relative luminance following the Luma recommendation BT. 709
• PERCEIVED: perceived luminance following the Luma recommendation CCIR 601

and a performance boost option:

• PERFORMANCE: trade accuracy for performance

Integration

Auto

Two-steps integration using JitPack

Manual

• Download the latest version
• Move it in the library folder of your project: libs/bright-1.0.aar
• Add the following dependency to your build.gradle

    repositories {
        flatDir {
            dirs 'libs'
        }
    }
    
    dependencies {
        compile 'com.devddagnet.bright.lib:bright:1.0@aar'
    }

Usage

Basic

Get the luminance of a color or an area

    int luminance = Bright.getInstance().brightness(color/rgb/bitmap);

Check if it is brighter than dark

    Bright.getInstance().isBright(luminance);

Or directly check from a color or an area

    Bright.getInstance().isBright(rgb/bitmap)

Options

Luminance variants: RELATIVE, PERCEIVED

Performance boost: PERFORMANCE

Get brightness from the relative luminance

    int luminance = Bright.setup(Config.RELATIVE).brightness(color/rgb/bitmap)

Get brightness from the perceived luminance

    int luminance = Bright.setup(Config.PERCEIVED).brightness(color/rgb/bitmap)

Trade accuracy for performance

    Bright.setup(Config.RELATIVE | Config.PERFORMANCE)

    Bright.setup(Config.PERCEIVED | Config.PERFORMANCE)

Sample

APK | Sources

MultiColorFragment - A set of colored blocks with a white or black text, relatively to the brightness of the text background color.

PictureFragment - A series of pictures with text in all corners and in the center, white or black relatively to the brightness of the background area

Bright(X) - X is the luminous intensity

Video

Glossary

Luminance: a photometric measure of the luminous intensity per unit area of light travelling in a given direction.

License

Copyright 2016 Damien Dagnet

Licensed 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.