我如何缩放伪彩色图像的colorbar
轴?
我阅读了这篇文章,并复制了代码,但似乎没有正确工作:
MATLAB Colorbar - Same colors, scaled values
请查看下面的两个图像。在第一张图中(未进行缩放),颜色轴范围为
[1 2 3 4 5 6]*10^4
在第二张图片中,它会继续进行。
[0.005 0.01 0.015 0.02 0.025]
正确的缩放(使用
C = 100000
)应为:[0.1 0.2 0.3 0.4 0.5 0.6]
没有缩放
![without scaling](https://istack.dev59.com/YvM6F.webp)
![wrong scaling](https://istack.dev59.com/rLFfk.webp)
1/C
进行缩放,并且我可以自由选择 C
,这样当像素值为 10^4
且 C=10^6
时,刻度应该显示 10^-2
。
我首先将图像乘以
C
是为了获得更多的小数位数,因为所有小于1的值在没有 C
缩放的情况下都会显示为零。当我运行代码时,我会得到一个名为
yticks
的工作区变量,其具有以下值:[500 1000 1500 2000 2500]
我的代码:
RGB = imread('IMG_0043.tif');% Read Image
info = imfinfo('IMG_0043.CR2'); % get Metadata
C = 1000000; % Constant to adjust image
x = info.DigitalCamera; % get EXIF
t = getfield(x, 'ExposureTime');% save ExposureTime
f = getfield(x, 'FNumber'); % save FNumber
S = getfield(x, 'ISOSpeedRatings');% save ISOSpeedRatings
date = getfield(x,'DateTimeOriginal');
I = rgb2gray(RGB); % convert Image to greyscale
K = 480; % Kamerakonstante(muss experimentel eavaluiert werden)
% N_s = K*(t*S)/power(f,2))*L
L = power(f,2)/(K*t*S)*C; %
J = immultiply(I,L); % multiply each value with constant , so the Image is Calibrated to cd/m^2
hFig = figure('Name','False Color Luminance Map', 'ToolBar','none','MenuBar','none');
% Create/initialize default colormap of jet.
cmap = jet(16); % or 256, 64, 32 or whatever.
% Now make lowest values show up as black.
cmap(1,:) = 0;
% Now make highest values show up as white.
cmap(end,:) = 1;
imshow(J,'Colormap',cmap) % show Image in false color
colorbar % add colorbar
h = colorbar; % define colorbar as variable
y_Scl = (1/C);
yticks = get(gca,'YTick');
set(h,'YTickLabel',sprintfc('%g', [yticks.*y_Scl]))
ylabel(h, 'cd/m^2')% add unit label
title(date); % Show date in image
caxis auto % set axis to auto
datacursormode on % enable datacursor
img = getframe(gcf);
nowstr = datestr(now, 'yyyy-mm-dd_HH_MM_SS');
folder = 'C:\Users\Taiko\Desktop\FalseColor\';
ImageFiles = dir( fullfile(folder, '*.jpg') );
if isempty(ImageFiles)
next_idx = 1;
else
lastfile = ImageFiles(end).name;
[~, basename, ~] = fileparts(lastfile);
file_number_str = regexp('(?<=.*_)\d+$', basename, 'match' );
last_idx = str2double(file_number_str);
next_idx = last_idx + 1;
end
newfilename = fullfile( folder, sprintf('%s_%04d.jpg', nowstr, next_idx) );
imwrite(img.cdata, newfilename);