brightness

How can I change the adaptive brightness level programmatically, on Android Lollipop? I know how to change the manual brightness level , and to toggle on or off the adaptive brightness . It is done like that: Settings.System.putInt(cr, Settings.System.SCREEN_BRIGHTNESS, newLevel); However, with adaptive brightness is enabled, the OS combines it with another brightness level which is different than the manual one. Is there a way to do this? Target/min/max SDK is 21. Don't know why but there is a hidden constant SCREEN_AUTO_BRIGHTNESS_ADJ in Android API to adjust adaptive brightness. But you can

I'm making an app that needs to toggle the screen on/off when the user shakes the phone. So far, I've got a SensorEventListener that listens to the shakes as suggested in the answer to this question . When I detect a shake, I change the value of the screen's brightness as suggested in this question's answer . It all works great if I don't actually turn the screen off... if I set the brightness to 0.01f through the public void setBright(float value) method it works perfectly. However, if I set the brightness to 0.0f, the phone won't turn the screen again... not until I press the power button,

I have an iOS 7 app where I want to make the screen darker. I am adjusting the screen brightness using the following line: [UIScreen mainScreen].brightness = 0.3; This dims the screen as I expect, but if a user has auto brightness enabled the screen sometimes goes back to its original setting. Is there a way to disable auto brightness while in my app, or do I need to subscribe to the UIScreenBrightnessDidChangeNotification notification and just reset the brightness each time it is raised? Legoless You cannot disable the auto brightness at all, so you will have to subscribe to the notification.

I want to adjust the brightness of an image to a certain value in OpenCV. For example, consider this image: I calculate the brightness with: import cv2 img = cv2.imread(filepath) cols, rows = img.shape brightness = numpy.sum(img) / (255 * cols * rows) and I get an average brightness of 35%. To bring it to 66%, for example, I do: minimum_brightness = 0.66 alpha = brightness / minimum_brightness bright_img = cv2.convertScaleAbs(img, alpha = alpha, beta = 255 * (1 - alpha)) and I get an image that seems to have a 50% transparency veil: I can avoid this effect by using bias only: bright_img = cv2

首先查看一下你的屏幕亮度值的范围： sudo cat /sys/class/backlight/acpi_video0/max_brightness 到了ubuntu14.10后，路径就变为了 /sys/class/backlight/intel_backlight/max_brightness.但改不改都没什么所谓了，因为14.10中 可以手动的调节光亮度，并且系统自动保存。再次启动系统的时候已经不需要再手动改了咯！ubuntu终于修改了这一设定了。 我的是15，也就是说亮度值可以在 0 ~ 15之间。 修改 /etc/rc.local ,在最后的 exit 0 之前添加： echo 3 > /sys/class/backlight/acpi_video0/brightness 系统完成启动最后会执行这个脚本，因此每次开机，都会把亮度值设置成3。 来源： oschina 链接： https://my.oschina.net/u/2289158/blog/479439

This will likely seem like a very easy thing I'm trying to do but Google search has not turned up exactly what I'm looking for and I'd like to do this correctly. Essentially I need to luminance match two bmps. They are simple circles (125x125 pixels) and their original color is only know to me by their (0-255 ranged) RGB value of 255,0,0. I need to find an RGB value of gray that is the same luminance of these circles. All other luminance/brightness matching tutorials I have seen have been for pictures that have included, a variety of hues, brightnesses, etc. and I am not sure if those