Re: What decides the Mono LCD gray scale?
From: cool_harber (cool_harber_at_hotmail.com)
Date: 12/30/04
- Next message: Chun: "Is DllEntry() the same as DllMain?"
- Previous message: Maju: "Does Wince 4.2 support Wake on LAN?"
- In reply to: voidcoder: "Re: What decides the Mono LCD gray scale?"
- Next in thread: voidcoder: "Re: What decides the Mono LCD gray scale?"
- Messages sorted by: [ date ] [ thread ]
Date: Thu, 30 Dec 2004 22:37:41 +0800
You can try
// These masks are used to extract the color component for a 16 bit pixel
value. 5 bits red, 6 bits green, 5 bits blue.
ulong BitMasks[] = {0xFFF, 0xFFFF, 0xFFFF};
Someone told me it can improve display effect.But I just got all black.:)
By the way,I found there is something wrong with my hardware but not
software.
Thank you~
"voidcoder" <voidcoder@yahoo.com> 写入消息新闻:e$F8IXn7EHA.2552@TK2MSFTNGP09.phx.gbl...
> Yes, it looks better!!!!
>
> Looks better because 0.299*R + 0.587*G + 0.114*B does not
> produce dublicates (eg. RGB(255, 0, 0) != RGB(0, 0, 255) ) as
> (R+G+B)/3 does.
>
> Thanks again and Happy New Year!!!! :-)
>
>
>
>
> "cool_harber" <cool_harber@hotmail.com> wrote in message
> news:#FYjO0m7EHA.128@TK2MSFTNGP15.phx.gbl...
>> 3x,I have tested the palette as you said,but the display is also bad,
>> Maybe my lcd just can be used in 4bpp.
>> A few days ago,Someone told me another palette in newsgroup,here is the
>> code:
>> // RGB to YUV conversion is defined by CCIR 601 Standard as
>>
>> // Y = 0.299*R + 0.587*G + 0.114 B
>>
>> // Implementation :
>>
>> // scale= 15
>>
>> // Gray = (Red*299 + Green*587 + Blue*114)*scale/(1000*255);
>>
>>
>> By the way,I use v_pPaletteBuffer->palette[ 0xFF - i ] to inverted
> palette.
>>
>> "voidcoder" <voidcoder@yahoo.com>
> 写入消息新闻:ebnNysa7EHA.3820@TK2MSFTNGP11.phx.gbl...
>> > Nothing special. Don't really sure that it is right, but
>> > I'm using just everage RGB value for grayscale level.
>> >
>> > eg.
>> >
>> > for(i=firstEntry;i<end;i++)
>> > {
>> > v_pPaletteBuffer->palette[ i ] =
>> > (((unsigned short)source[i].peBlue + source[i].peGreen +
>> > source[i].peRed) / 3);
>> > }
>> >
>> > The better result is using inverted average value, eg
>> >
>> >
>> > v_pPaletteBuffer->palette[ i ] =
>> > 0x00FF ^ (((unsigned short)source[i].peBlue +
> source[i].peGreen
>> > +
>> > source[i].peRed) / 3);
>> >
>> > Please test it and come back with comments (since I think
>> > this is not really right way to calculate grayscale palette).
>> >
>> > May be any1 can share some ideas on "how to calculate right
>> > grayscale palette"?
>> >
>> >
>> >
>> > "cool_harber" <cool_harber@hotmail.com> wrote in message
>> > news:OnQDrka7EHA.2124@TK2MSFTNGP15.phx.gbl...
>> >> Thanks,But my lcd display looks so bad,
>> >> the text is more clear than the blurred icon or image!~
>> >> Can you share me your palette source code?
>> >> email:cool_harber@hotmail.com
>> >>
>> >> "voidcoder" <voidcoder@yahoo.com>
>> > 写入消息新闻:eLG5VDP7EHA.2316@TK2MSFTNGP15.phx.gbl...
>> >> > If You want to use SA_Lcd driver for that - you are out of luck.
>> >> > There are no support for true 4bpp mode. However you can use
>> >> > 8bpp mode and turn on monochrome mode in the controller.
>> >> > Then just setup your palette with grayscale entries
>> >> > (modify DispDrvrSetPalette function). In this case You will have
>> >> > 8bpp in frame buffer memory, 4bpp output and 16bit lookup palette
>> >> > (where only lower 8bits are grayscale values). And of course
>> >> > You have to setup other LCD contoller settings: timings, clocks etc.
>> >> >
>> >> > At least it works o.k. for me on PXA270.
>> >> >
>> >> >
>> >> >
>> >> > "cool_harber" <cool_harber@hotmail.com> wrote in message
>> >> > news:eN2ZwbO7EHA.3076@TK2MSFTNGP15.phx.gbl...
>> >> >> The mono lcd`s gray scale is decided by lcd controller or lcd
> itself?
>> >> >> I have a mono lcd with 4 data pins and about 70 Hz frame frequence
> ,I
>> >> >> want to use PXA255 to controll it.Do I get 256 scale gray?
>> >> >> Any suggestion is appreciated.
>> >> >>
>> >> >>
>> >> >
>> >> >
>> >>
>> >>
>> >
>> >
>>
>>
>
>
- Next message: Chun: "Is DllEntry() the same as DllMain?"
- Previous message: Maju: "Does Wince 4.2 support Wake on LAN?"
- In reply to: voidcoder: "Re: What decides the Mono LCD gray scale?"
- Next in thread: voidcoder: "Re: What decides the Mono LCD gray scale?"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
|
