矩陣擴展

爲了方便對圖像邊界的處理，通常要把圖像矩陣進行擴展。

原圖：

代碼：

fig = figure('NumberTitle', 'off', 'name', 'Happy');  
hold on;
  
LineWidth = 2;  
FontSize = 12;  
MarkerSize = 3;  
  
for i = 1 : 9  
    plot([i i], [-1 -9], 'k', 'LineWidth', LineWidth);  
    plot([1 9], [-i -i], 'k', 'LineWidth', LineWidth);  
end  

% 上下
for j = 3 : 8
    text(j-0.5, -1.5, ['U'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(j-0.5, -8.5, ['D'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
end

% 左右
for i = 3 : 8
    text(1.5, -i+0.5, ['L'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(8.5, -i+0.5, ['R'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
end

% 四角
text(1.5, -1.5, 'UL', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
text(8.5, -1.5, 'UR', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
text(1.5, -8.5, 'DL', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
text(8.5, -8.5, 'DR', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
  
axis equal;  
axis off;  

擴展圖：

代碼：

fig = figure('NumberTitle', 'off', 'name', 'Happy');  
hold on;
  
LineWidth = 2;  
FontSize = 12;  
MarkerSize = 3;  
  
for i = 0 : 10  
    plot([i i], [0 -10], 'k', 'LineWidth', LineWidth);  
    plot([0 10], [-i -i], 'k', 'LineWidth', LineWidth);  
end  

% 上下
for j = 3 : 8
    text(j-0.5, -0.5, ['U'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(j-0.5, -1.5, ['U'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(j-0.5, -8.5, ['D'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(j-0.5, -9.5, ['D'  num2str(j-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
end

% 左右
for i = 3 : 8
    text(0.5, -i+0.5, ['L'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(1.5, -i+0.5, ['L'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(8.5, -i+0.5, ['R'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    text(9.5, -i+0.5, ['R'  num2str(i-1)], 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
end

% 四角
for i = 1 : 2
    for j = 1 : 2
        text(j-0.5, -i+0.5, 'UL', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
        text(j+7.5, -i+0.5, 'UR', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
        text(j-0.5, -i-7.5, 'DL', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
        text(j+7.5, -i-7.5, 'DR', 'FontSize', FontSize, 'FontWeight', 'bold', 'HorizontalAlignment', 'center');
    end
end

% 框出原圖
plot([1 9], [-1 -1], 'r', 'LineWidth', LineWidth+1);  
plot([9 9], [-1 -9], 'r', 'LineWidth', LineWidth+1);  
plot([9 1], [-9 -9], 'r', 'LineWidth', LineWidth+1);  
plot([1 1], [-9 -1], 'r', 'LineWidth', LineWidth+1);  

% 框出擴展方法
plot([0 10], [-2 -2], 'b', 'LineWidth', LineWidth+1);  
plot([0 10], [-8 -8], 'b', 'LineWidth', LineWidth+1);  
plot([2 2], [0 -10], 'b', 'LineWidth', LineWidth+1);  
plot([8 8], [0 -10], 'b', 'LineWidth', LineWidth+1);  
  
axis equal;  
axis off;