一个16位的转换相对8位色 [英] relative 8-bit color of a 16-bit conversion
问题描述
我工作的Java EE应用程序,其中我有一个项目,将包含一些产品的表,字段来设置它的颜色。
I am working on a Java EE application, in which I have a table of "items" which will contain some products, and a field to set its color.
问题:用户从一个包含16或者128种颜色的调色板选择一种颜色。我存储的颜色为一个字节(8位色),而我需要能够为RGB颜色/整数转换成它的8位等效,反之亦然,例如:
The Problem: The user chooses a color from a palette that contains 16 or perhaps 128 colors. I am storing the color as a byte (8-bit color), and I need to be able to convert RGB color/integer to its 8-bit equivalent and vice-versa, e.g.:
White: 0xFF(0b 111 111 11) to -1 or (255,255,255)
Red: 0x10(0b 111 000 00) to -65536 or (255, 0, 0 )
我已经试过到目前为止:
What I have tried so far:
void setColor(Color color){
short sColor = (color.getRGB() >> 16) & 0xFF) >> 8
| (color.getRGB() >> 8) & 0xFF) >> 8
| (color.getRGB() >> 0) & 0xFF) >> 8;
}
Color getColor(short sColor){
Color rgb = new Color(
/*red:*/ (sColor & 0xF) << 16,
/*gree:*/ (sColor & 0xF) << 8,
/*blue*/ (sColor & 0xF) << 0));
}
/* or */
Color getColor(short sColor){
Color rgb = new Color((sColor << 8) + sColor));
}
当我通过颜色值0到255环,我得到一个单一的色调变化。
When I loop through color values 0 to 255, I get a single hue variations.
推荐答案
因此,在8位色彩:
So in the 8 bit color:
111 111 11
red grn bl
使用红色和绿色8个不同的值:
With 8 different values for red and green:
0 (0)
1 (36)
2 (72)
3 (109)
4 (145)
5 (182)
6 (218)
7 (255)
和4个不同的值,蓝色。
And 4 different values for blue.
试试这个:
public static Color fromByte(byte b) {
int red = (int) Math.round(((b & 0xE0) >>> 5) / 7.0 * 255.0);
int green = (int) Math.round(((b & 0x1C) >>> 2) / 7.0 * 255.0);
int blue = (int) Math.round((b & 0x03) / 3.0 * 255.0);
return new Color(red, green, blue);
}
public static byte fromColor(Color color) {
int red = color.getRed();
int green = color.getGreen();
int blue = color.getBlue();
return (byte) (((int) Math.round(red / 255.0 * 7.0) << 5) |
((int) Math.round(green / 255.0 * 7.0) << 2) |
((int) Math.round(blue / 255.0 * 3.0)));
}
下面是可能的颜色 http://jsfiddle.net/e3TsR/
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