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Technology / How does altering a smart phone's gray-scale on help with battery life?
« on: 05/06/2014 17:50:10 »
Greetings. The gray scale mode of the new Samsung Galaxy S5 is really bothering me.
Many people, without deeper knowledge and understanding, automatically think that a grayscale screen will require less power - but is it true?
Lets see:
First of all, the screen is not black and white, but grayscale - there is a difference.
In order to get a gray pixel, all three sub-pixels (RGB) must be active (if all are at max levels then it will be white.. as gray is dark-white). And from the looks of it, the images on such a grayscale mode screen are mostly .. gray, not fully black.
Wouldnt a, for example, dark blue tone need less power than a gray tone, as it would need only one color sub-pixlel to be active?
What does actually reduce power consumption:
*Reduce the color depth (grayscale probably does this, but it is not advertised as such) - less bits per color to be stored in video RAM and processed.
*Reduce the brightness of the screen. (the grayscale seems a bit darker, but the screen can be made darker keeping the colors and, perhaps, adjusting contrast for better viewing)
*Reduce the resolution - less pixels to be processed and stored in RAM (damn, people want 4K screens in their devices and cry about how bad the accumulators are, phew)
*Make the screen ACTUALLY black with some white (or gray, or single color) marking what needs to be seen.
*Reduce the refresh rate, perhaps.
*What else.. ?
All this can actually lower the power consumption, but how exactly does simply making the screen gray-scale helps?
Many people, without deeper knowledge and understanding, automatically think that a grayscale screen will require less power - but is it true?
Lets see:
First of all, the screen is not black and white, but grayscale - there is a difference.
In order to get a gray pixel, all three sub-pixels (RGB) must be active (if all are at max levels then it will be white.. as gray is dark-white). And from the looks of it, the images on such a grayscale mode screen are mostly .. gray, not fully black.
Wouldnt a, for example, dark blue tone need less power than a gray tone, as it would need only one color sub-pixlel to be active?
What does actually reduce power consumption:
*Reduce the color depth (grayscale probably does this, but it is not advertised as such) - less bits per color to be stored in video RAM and processed.
*Reduce the brightness of the screen. (the grayscale seems a bit darker, but the screen can be made darker keeping the colors and, perhaps, adjusting contrast for better viewing)
*Reduce the resolution - less pixels to be processed and stored in RAM (damn, people want 4K screens in their devices and cry about how bad the accumulators are, phew)
*Make the screen ACTUALLY black with some white (or gray, or single color) marking what needs to be seen.
*Reduce the refresh rate, perhaps.
*What else.. ?
All this can actually lower the power consumption, but how exactly does simply making the screen gray-scale helps?