如何去掉图像四周的白边 – MATLAB中文论坛

Posted 2023-03-21

参考技术A clc; close all; clear;
I = imread('peoplewalk.jpg');

fg = figure;
set(fg, 'name', 'view picture');
set(fg, 'numbertitle', 'off');
set(fg, 'toolbar', 'none');
set(fg, 'units', 'pixel');
pos = get(fg, 'position');
set(fg, 'position', [pos(1) pos(2)-80 size(I, 2) size(I, 1)]);
set(gca, 'units', 'pixel');
set(gca, 'position', [0 0 size(I, 2) size(I, 1)]);
imshow(I, []);

%加上自己要对图像处理的命令。% 参考技术B 把这个函数放到当前文件夹下，生成图像之后运行这个函数即可
tightfig
function hfig = tightfig(hfig)
% tightfig: Alters a figure so that it has the minimum size necessary to
% enclose all axes in the figure without excess space around them.
%
% Note that tightfig will expand the figure to completely encompass all
% axes if necessary. If any 3D axes are present which have been zoomed,
% tightfig will produce an error, as these cannot easily be dealt with.
%
% Input
%
% hfig - handle to figure, if not supplied, the current figure will be used
% instead.
%
%
if nargin == 0
hfig = gcf;
end
% There can be an issue with tightfig when the user has been modifying
% the contnts manually, the code below is an attempt to resolve this,
% but it has not yet been satisfactorily fixed
% origwindowstyle = get(hfig, 'WindowStyle');
set(hfig, 'WindowStyle', 'normal');

% 1 point is 0.3528 mm for future use
% get all the axes handles note this will also fetch legends and
% colorbars as well
hax = findall(hfig, 'type', 'axes');
% TODO: fix for modern matlab, colorbars and legends are no longer axes
hcbar = findall(hfig, 'type', 'colorbar');
hleg = findall(hfig, 'type', 'legend');

% get the original axes units, so we can change and reset these again
% later
origaxunits = get(hax, 'Units');

% change the axes units to cm
set(hax, 'Units', 'centimeters');

pos = [];
ti = [];

% get various position parameters of the axes
if numel(hax) > 1
% fsize = cell2mat(get(hax, 'FontSize'));
ti = cell2mat(get(hax,'TightInset'));
pos = [pos; cell2mat(get(hax, 'Position')) ];
else
% fsize = get(hax, 'FontSize');
ti = get(hax,'TightInset');
pos = [pos; get(hax, 'Position') ];
end

if ~isempty (hcbar)

set(hcbar, 'Units', 'centimeters');

% colorbars do not have tightinset property
for cbind = 1:numel(hcbar)
% fsize = cell2mat(get(hax, 'FontSize'));
[cbarpos, cbarti] = colorbarpos (hcbar);
pos = [pos; cbarpos];
ti = [ti; cbarti];
end
end

if ~isempty (hleg)

set(hleg, 'Units', 'centimeters');

% legends do not have tightinset property
if numel(hleg) > 1
% fsize = cell2mat(get(hax, 'FontSize'));
pos = [pos; cell2mat(get(hleg, 'Position')) ];
else
% fsize = get(hax, 'FontSize');
pos = [pos; get(hleg, 'Position') ];
end
ti = [ti; repmat([0,0,0,0], numel(hleg), 1); ];
end

% ensure very tiny border so outer box always appears
ti(ti < 0.1) = 0.15;

% we will check if any 3d axes are zoomed, to do this we will check if
% they are not being viewed in any of the 2d directions
views2d = [0,90; 0,0; 90,0];

for i = 1:numel(hax)

set(hax(i), 'LooseInset', ti(i,:));
% set(hax(i), 'LooseInset', [0,0,0,0]);

% get the current viewing angle of the axes
[az,el] = view(hax(i));

% determine if the axes are zoomed
iszoomed = strcmp(get(hax(i), 'CameraViewAngleMode'), 'manual');

% test if we are viewing in 2d mode or a 3d view
is2d = all(bsxfun(@eq, [az,el], views2d), 2);

if iszoomed && ~any(is2d)
error('TIGHTFIG:haszoomed3d', 'Cannot make figures containing zoomed 3D axes tight.')
end

end

% we will move all the axes down and to the left by the amount
% necessary to just show the bottom and leftmost axes and labels etc.
moveleft = min(pos(:,1) - ti(:,1));

movedown = min(pos(:,2) - ti(:,2));

% we will also alter the height and width of the figure to just
% encompass the topmost and rightmost axes and lables
figwidth = max(pos(:,1) + pos(:,3) + ti(:,3) - moveleft);

figheight = max(pos(:,2) + pos(:,4) + ti(:,4) - movedown);

% move all the axes
for i = 1:numel(hax)

set(hax(i), 'Position', [pos(i,1:2) - [moveleft,movedown], pos(i,3:4)]);

end

for i = 1:numel(hcbar)

set(hcbar(i), 'Position', [pos(i+numel(hax),1:2) - [moveleft,movedown], pos(i+numel(hax),3:4)]);

end

for i = 1:numel(hleg)

set(hleg(i), 'Position', [pos(i+numel(hax)+numel(hcbar),1:2) - [moveleft,movedown], pos(i+numel(hax)+numel(hcbar),3:4)]);

end

origfigunits = get(hfig, 'Units');

set(hfig, 'Units', 'centimeters');

% change the size of the figure
figpos = get(hfig, 'Position');

set(hfig, 'Position', [figpos(1), figpos(2), figwidth, figheight]);

% change the size of the paper
set(hfig, 'PaperUnits','centimeters');
set(hfig, 'PaperSize', [figwidth, figheight]);
set(hfig, 'PaperPositionMode', 'manual');
set(hfig, 'PaperPosition',[0 0 figwidth figheight]);

% reset to original units for axes and figure
if ~iscell(origaxunits)
origaxunits = origaxunits;
end
for i = 1:numel(hax)
set(hax(i), 'Units', origaxunitsi);
end
set(hfig, 'Units', origfigunits);

% set(hfig, 'WindowStyle', origwindowstyle);

end
function [pos, ti] = colorbarpos (hcbar)
% 1 point is 0.3528 mm

pos = hcbar.Position;
ti = [0,0,0,0];

if ~isempty (strfind (hcbar.Location, 'outside'))
if strcmp (hcbar.AxisLocation, 'out')

tlabels = hcbar.TickLabels;

fsize = hcbar.FontSize;

switch hcbar.Location

case 'northoutside'

% make exta space a little more than the font size/height
ticklablespace_cm = 1.1 * (0.3528/10) * fsize;

ti(4) = ti(4) + ticklablespace_cm;

case 'eastoutside'

maxlabellen = max ( cellfun (@numel, tlabels, 'UniformOutput', true) );

% 0.62 factor is arbitrary and added because we don't
% know the width of every character in the label, the
% fsize refers to the height of the font
ticklablespace_cm = (0.3528/10) * fsize * maxlabellen * 0.62;
ti(3) = ti(3) + ticklablespace_cm;

case 'southoutside'

% make exta space a little more than the font size/height
ticklablespace_cm = 1.1 * (0.3528/10) * fsize;
ti(2) = ti(2) + ticklablespace_cm;

case 'westoutside'

maxlabellen = max ( cellfun (@numel, tlabels, 'UniformOutput', true) );

% 0.62 factor is arbitrary and added because we don't
% know the width of every character in the label, the
% fsize refers to the height of the font
ticklablespace_cm = (0.3528/10) * fsize * maxlabellen * 0.62;
ti(1) = ti(1) + ticklablespace_cm;

end
end
end
end

LaTeX：svg图片转pdf，以及pdf图片去白边

参考技术A

需求：在利用geogebra绘制图像并保存，发现隐藏坐标网格后，保存图片的四周有大面积的" 白边 "；将这种带白边儿的图片直接插入latex中是很难看的！因此需要将白边删除，且要保持删除规则/范围一致（同一系列的图，删完白边后图片大小要相同，即删边的规则要一定）！

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