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如何rgb2ycbcr在 Octave 中将输出转换回 RGB？我在包中
找不到ycbcr2rgb函数。image

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2 回答 2

2

这里有一个有用的功能可以做到这一点（复制如下）

%Copyright (C) 2005  Berge-Gladel

%This program is free software; you can redistribute it and/or
%modify it under the terms of the GNU General Public License
%as published by the Free Software Foundation; either version 2
%of the License, or (at your option) any later version.

%This program is distributed in the hope that it will be useful,
%but WITHOUT ANY WARRANTY; without even the implied warranty of
%MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%GNU General Public License for more details.

function nouvmat2 = ycbcr2rgb(in)

%   YCBCR2RGB Convert YCbCr values to RGB color space.
%   RGBMAP = YCBCR2RGB(YCBCRMAP) converts the YCbCr values in the
%   colormap YCBCRMAP to the RGB color space. If YCBCRMAP is M-by-3 and
%   contains the YCbCr luminance (Y) and chrominance (Cb and Cr) color
%   values as columns, then RGBMAP is an M-by-3 matrix that contains
%   the red, green, and blue values equivalent to those colors.
%
%   RGB = YCBCR2RGB(YCBCR) converts the YCbCr image to the equivalent
%   truecolor image RGB
%   

    % cas ou on a une image (s est la taille de l'image en pixels)
    %matrice(:,:,:) = colormap(map) ; 
    % attention, on a des valeurs entre 0 et 1
    m=size(in);

    nbligmat = m(1);
    nbcolmat = m(2);

    nouvmat2 = ones(nbligmat,nbcolmat);

    % on multiplie par 255
    matrice = in *255;

    for i = 1 : nbligmat
        %  R = Y + 1.402*(Cr-128)
        nouvmat2(i,1) = matrice(i,1,:) + 1.402 * (matrice(i,3,:) - 128);
        %  G = Y - 0.34414 (Cb-128) - 0.71414 (Cr-128)
        nouvmat2(i,2) = matrice(i,1,:) - 0.34414 * (matrice(i,2,:) - 128) - 0.71414 * (matrice(i,3,:) - 128);
        %  B = Y + 1.772 * (Cb-128)
        nouvmat2(i,3) = matrice(i,1,:) + 1.772 * (matrice(i,2,:) - 128);
    end


    % on divise par 255 pour rendre une matrice avec des valeurs entre 0 et 1
        nouvmat2 = nouvmat2 / 255;

    for i = 1 : nbligmat
        for j = 1 : nbcolmat
            if nouvmat2(i,j) < 0
                nouvmat2(i,j) = 0;
            end
        end
    end
 endfunction
于 2013-05-05T09:15:21.300 回答
1

我刚刚完成了 Octave 镜像包的重写rgb2ycbcr和实现ycbcr2rgb。它将成为下一个图像包版本的一部分（可能在夏末发生）。只需克隆映像包存储库或手动下载各个功能：

于 2013-05-05T16:26:46.587 回答