Question

somebdy可以解释这段代码如何将彩色图片变成黑白图片吗？

Begin
  Indeks := 3 * Kolom;
  R := PDataBaris[Indeks];
  G := PDataBaris[Indeks + 1];
  B := PDataBaris[Indeks + 2];

  Intensitas := Round(0.2989 * R + 0.5870 * G + 0.1141 * B);

  if Intensitas < 128 then
  begin
    p := p + 1;
    Intensitas := 0
  end;

  if Intensitas > 128 then
  begin
    h := h + 1;
    Intensitas := 255
  end;

  PDataBaris[Indeks] := Intensitas;
  PDataBaris[Indeks + 1] := Intensitas;
  PDataBaris[Indeks + 2] := Intensitas;
End;

Answer 1

此代码使用标准公式将RGB颜色转换为其强度（灰度），用于YUV模型，为电视开发。 Luma coding here

在PAL和NTSC使用的Y'UV和Y'IQ模型中，rec601亮度（Y'）分量计算为Y = 0.299 * R + 0.587 * G + 0.114 * B

我希望其他操作清晰 - 灰度图像被二值化 - 浅色（高强度值）变白，暗色变黑。

Answer 2

Begin
  //there is an array of RGB values of a picture
  //every third value is the blue value
  Indeks := 3 * Kolom;
  R := PDataBaris[Indeks];  //red
  G := PDataBaris[Indeks + 1]; //green
  B := PDataBaris[Indeks + 2];  //blue

  //calulate brightness
  //human vision is most sensitive to green and least sensitive to blue
  Intensitas := Round(0.2989 * R + 0.5870 * G + 0.1141 * B);

  //convert to black/white
  //without the added = you'll have 3 values (white, gray, black)
  if Intensitas <= 128 then   
  begin
    p := p + 1;
    Intensitas := 0
  end;

  if Intensitas > 128 then
  begin
    h := h + 1;
    Intensitas := 255
  end;

  //if r=g=b you have a gray value
  //based on the code above there are only two (three) values possible:
  //black(0) and white(255) (ev. gray (128))
  PDataBaris[Indeks] := Intensitas;  //red
  PDataBaris[Indeks + 1] := Intensitas;  //green 
  PDataBaris[Indeks + 2] := Intensitas;  //blue
End;

这段代码如何将彩色图片改为黑白图片

2 个答案: