How can I find a path for each letter containing a list of x and y values?

Question

Mohammad Rastegarpanah 2022-10-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1821460-how-can-i-find-a-path-for-each-letter-containing-a-list-of-x-and-y-values

编辑： DGM 2023-9-27

在 MATLAB Online 中打开

For example;

For letter M: path1= [ [x1 y1], [x2 y2],...];
For letter A: path2= [ [x1 y1], [x2 y2],...];
For letter X: path3= [ [x1 y1], [x2 y2],...];

Thanks,

figure

ax=gca;

t = text(0.05,0.05,'MAX');

s = t.FontSize;

t.FontSize = 50;

ax.Visible='on';

grid on

9 个评论
显示 7更早的评论隐藏 7更早的评论

Mohammad Rastegarpanah 2022-10-10

在 MATLAB Online 中打开

clc

clear

close(allchild(0))

% Start with figure

f = figure();

xlim([1 118]) % set x-axis visible on figure

ylim([1 20]) % set y-axis visible on figure

hold on %keep all lines on one figure

%axis off %removes plot view

% letter D

% break it down - line and curve

x_D_line = [5 5];

y_D_line = [5 15];

plot(x_D_line,y_D_line,'r','LineWidth',2)

%plot(x_D_line,y_D_line,'r','LineWidth',2) %(make D red with 'r' input argument)

x_D_curve = -10:.1:10;

y_D_curve = (x_D_curve.^2)/10; %divide to flatten curve some

% rotate curve 90* counter clockwise about the origin (-y,x)

plot(-y_D_curve+15,x_D_curve/2+10,'r','LineWidth',2) % add to x an y to shift

% plot(-y_D_curve+15,x_D_curve/2+10,'r','LineWidth',2) %(make D red with 'r' input argument)

% spans 5 to 15 on y

% spans 5 to 15 on x

% letter r

x_r_line = [20 20];

y_r_line = [5 10];

plot(x_r_line,y_r_line)

x = -2:.1:4;

y = (x.^2)/20; %divide to flatten curve some

% flip vertically (x,-y)

plot(x+22,-y+10)

% stops at 26 on x-axis

Thanks for your reply,

What I expect at the end the receive critical points (x, and y) values for each letter. In this example, the corresponding x and y values are defined separately for each letter manually.

However, in this problem I want to receive x, and y values when I entered input.

Mohammad Rastegarpanah 2022-10-11

编辑：Mohammad Rastegarpanah 2022-10-11

在 MATLAB Online 中打开

@Jan It's not an image; for example, I defined some points (containing x and y values), resulting in the letters M and O!

% Start with figure

f = figure();

xlim([1 118]) % set x-axis visible on figure

ylim([1 20]) % set y-axis visible on figure

hold on %keep all lines on one figure

grid on

% letter M

x1 = [1, 1, 5, 9, 9];

y1 = [0, 10, 5, 10, 0];

M = plot(x1,y1,'r','LineWidth',2);

%letter O

r = 5; % radius

xc = 20;

yc = 5;

theta = linspace(0,2*pi,100);

x2 = r*cos(theta);

y2 = r*sin(theta);

x2 = x2+20;

y2 = y2+5;

O = plot(x2,y2,'r','LineWidth',2);

axis equal

Now let's consider the opposite way; you want to give some letters that can be a name, for example, MAX, and in the output, you can have a list of x and y values for each letter M, A, X separately.

figure

ax=gca;

t = text(0.05,0.05,'MAX');

s = t.FontSize;

t.FontSize = 50;

ax.Visible='on';

grid on

The last example is a figure. Consequently, I think it's impossible to extract x and y values.

Is there any alternative way to solve this problem?

Jan 2022-10-11

@Mohammad Rastegarpanah: The question is still not clear. "you want to give some letters" - what exactly do you call "some letters"? You post a pixel image, which contains some letters (but an axes and their labels also).

What exactly is the input you start with? Do not think in categories like "some letters", but in objects as Matlab can see them: arrays which are coordinates or pixel values or what ever.

Then define, what "x and y values" mean. Values of what? The M is a polygon with 13 corners. Then what do you exactly want as output?

I still think, you want a vectorization of a pixel image. This is solved e.g. by inkScape.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

DGM 2023-9-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1821460-how-can-i-find-a-path-for-each-letter-containing-a-list-of-x-and-y-values#answer_1320424

编辑：DGM 2023-9-27

在 MATLAB Online 中打开

If you're trying to vectorize text, and aren't terribly concerned with the font, you could just start with text that's already in vector form. For this, I'm just going to use any pedestrian 2D CAD software to write some text containing the desired characters separated by spaces. Pay attention to the text size, and place it at the origin. Explode the MTEXT object and save the file.

Then, use DXFtool() to read the file. The reason the text is exploded (converted into primitives) is because DXFtool can't read MTEXT. The reason the characters are spaced apart is so that we can tell which primitives belong to which character.

% these are the characters in the DXF

charset = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';

% this is the nominal character height

charheight = 1; % whatever you used in the DXF

% DXFtool can't read mtext entities

% but if you explode the text, it can read the primitives

% DXFtool will open a figure; we don't really need that

dxf = DXFtool('vectortext.dxf.txt'); % fake extension for the forum

% of course, once exploded, the primitives aren't associated anymore

% so we have to group them back into characters somehow

% i'm just going to do this based on the character size and distance between chars

% i'm presuming character width is less than character height

n = 1; % initialize

C = cell(1);

for k = 1:dxf.ne

x = dxf.entities(k).handle.XData;

y = dxf.entities(k).handle.YData;

if k == 1

lastxmax = max(x);

end

% if point lists are distant (in x), start a new character

% otherwise, append to the current character

if min(x) > (lastxmax + charheight)

n = n+1;

C{n} = [x(:) y(:)];

else

C{n} = [C{n}; nan(1,2); [x(:) y(:)]];

end

lastxmax = max(x);

end

% go through the characters and remove their x-offsets

for k = 1:numel(C)

C{k}(:,1) = C{k}(:,1) - min(C{k}(:,1));

end

% now you can just save C and charset for later use

save('vectortext.mat','C','charset')

Now we have a character set represented in a char vector, and we have a corresponding set of x-y point lists. Given any new text, we can just draw it.

%% when you want to convert text, use the collected info

% the inputs

mytext = '256 Bananas';

charspacing = 0.25;

spacewidth = 0.55;

% initial position

x0 = 0;

y0 = 0;

% load C and charset

load vectortext.mat

% plot the things

figure

for k = 1:numel(mytext)

thischar = mytext(k);

% check to see if this character is in the charset

% if it's not, do something

if ~any(charset == thischar,2)

if thischar == ' '

% if it's a space, we know what to do with that

x0 = x0 + spacewidth;

end

% otherwise, just skip unknown characters

continue;

end

% get xy data for this character

idx = find(charset == thischar);

x = C{idx}(:,1);

y = C{idx}(:,2);

% shift x as needed

cw = max(x);

x = x + x0;

x0 = x0 + cw + charspacing; % update x0

% shift y as needed

y = y + y0;

plot(x,y); hold on

end

axis equal

This example is hardly robust or complete, but it's enough to demonstrate the idea.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

How can I find a path for each letter containing a list of x and y values?

9 个评论
显示 7更早的评论隐藏 7更早的评论

回答（1 个）

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

另请参阅

类别

标签

Community Treasure Hunt

How can I find a path for each letter containing a list of x and y values?

9 个评论 显示 7更早的评论隐藏 7更早的评论

回答（1 个）

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

另请参阅

类别

标签

Community Treasure Hunt

9 个评论
显示 7更早的评论隐藏 7更早的评论

0 个评论
显示 -2更早的评论隐藏 -2更早的评论