Stack Overflow
Stack Overflow

Questions tagged [brightness]

An attribute of visual perception in which a source appears to be radiating or reflecting light.

Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. This is a subjective attribute/property of an object being observed.

478 questions
3
votes
3 answers

Changing monitor brightness programatically in Ubuntu 11.10

I'm using Dell inspiron 1564 laptop with Ubuntu 11.10. Here I can change my monior brightness simply via fn+F4/5. But I need a low brightness even lower than the min limit of fn+F4. How can I do it programatically or which shell command to use for…
Dewsworld
  • 13,367
  • 23
  • 68
  • 104
3
votes
2 answers

how to calculate Brightness of RGB color?

i've got my function: -(void)rgbToHSBWithR:(float)red G:(float)green B:(float)blue { float brightness = red * 0.3 + green * 0.59 + blue * 0.11; // found in stackoverflow NSLog(@"%f",brightness); } and it isn't work for me. for example: r:84 g:67…
Tomasz Szulc
  • 4,217
  • 4
  • 43
  • 79
3
votes
3 answers

Trying to set screen brightness on android phone

I am trying to set the screen brightness but when I try and get the current window with this.getWindow() I get null. Why is this? I will post all of my code in my setBrightness() method. System.putInt(getContentResolver(), System.SCREEN_BRIGHTNESS, …
plast
  • 213
  • 2
  • 11
3
votes
1 answer

WPF image manipulation

I have some idea of changing brightness in contrast, but i was wondering had a simple solution for changing brightness and contrast
Rad
3
votes
4 answers

How can I make changes to android screen brightness persistent?

I've managed to change screen brightness within an activity (and by extension the entire app) using the following code: Settings.System.putFloat(this.getContentResolver(),Settings.System.SCREEN_BRIGHTNESS,…
dckrooney
  • 3,041
  • 3
  • 22
  • 28
3
votes
2 answers

Controlling Contrast and Brightness of Video Stream in OpenCV and Python

I’m using OpenCV3 and Python 3.7 to capture a live video stream from my webcam and I want to control the brightness and contrast. I cannot control the camera settings using OpenCV's cap.set(cv2.CAP_PROP_BRIGHTNESS, float) and…
slalomchip
  • 779
  • 2
  • 9
  • 25
3
votes
1 answer

How to detect the brightness programmatically

I am creating an application for iPad which can change the images by detecting the brightness of the room. So I want to know is there a way to detect the brightness of the room ?
Lena
  • 1,400
  • 3
  • 14
  • 20
3
votes
2 answers

How to check brightness of a background color to decide text color written on it

I have a simple question, but I wasn't able to find an answer to this. Note, that I'm almost a complete beginner. So I have an app (it's not mine, but I'm contributing to it), and in there is writing on a color background, which can be changed by…
RedyAu
  • 67
  • 1
  • 9
3
votes
0 answers

Change Brightness of image same as Photoshop using Color Matrix

In Photoshop, we can change the Brightness of image within the range of -150 to 150. Using PhotoshopCS4: Image →　Adjustments →　Brightness/Contrast. We set this level to 30 for a particular image (A.jpg) and save the image (A_30Bright.jpg) Used same…
Banng
  • 531
  • 1
  • 6
  • 19
3
votes
3 answers

iphone - Change the screen brightness, like iBook does

In iBook, user can adjust the screen brightness via a slider, right? What should I do to implement that? Which class or function I should use to control the screen brightness? Thanks
Jack
  • 3,913
  • 8
  • 41
  • 66
3
votes
1 answer

iPhone brightness private API not working properly

I am trying to set the brightness of the backlight, but it's acting very strangely. I am using the private API: [(id)[UIApplication sharedApplication] setBacklightLevel:1.0f]; However, when I call this, the screen dims, not becoming 100% bright like…
Ned
  • 6,280
  • 2
  • 30
  • 34
3
votes
2 answers

Change Brightness using WMI

I have tried this Windows example Getting WMI Data from a Remote Computer and this other Calling a Provider Method, and both work correctly in my computer. However I have tried to use WMI to change the brightness and I am getting an error on step 6,…
Miguel
  • 198
  • 2
  • 12
3
votes
3 answers

Android 2.2: Adjusting screen brightness

public void SetBright(float value) { Window mywindow = getWindow(); WindowManager.LayoutParams lp = mywindow.getAttributes(); lp.screenBrightness = value; mywindow.setAttributes(lp); } I want to adjust the…
Johan
  • 427
  • 2
  • 7
  • 14
3
votes
2 answers

Change CSS-Style Color Value with JavaScript

I have a box with a style that sets the color of the box to var(--box-color). This variable is defined in a separate CSS file, which I use for constants etc.: :root{ --box-color: rgba(250,250,250,1.0); } I want to make the color of the box lighter…
d0n.key
  • 1,318
  • 2
  • 18
  • 39
3
votes
1 answer

Opencv split and change value in that channel in android

I want to adjust the brightness of frame in opencv camera which is called mRgba. After I split the channel of lab. I hope to adjust the L channel but I don't know how to change the value in the L channel. Mat lab_image = new Mat(); //mRgba is…
ng2b30
  • 351
  • 6
  • 18
1 2 3
…
31 32