file.
LI Xu's World
LI Xu (LI Hsu), Ph.D. in Management
Wednesday, April 24, 2024
Wednesday, April 17, 2024
Saturday, April 6, 2024
ENVI: Instructions for converting ENVI format classification maps to GEOTIFF format
[1] Open the ENVI format classification image, such as image 2003; at this point, the image's save format is ENVI Classification, which can be checked by editing the image's header file (Edit Header). The method is to right-click on 2003 in the Available Bands List, and from the pop-up menu select Edit Header, as shown in the image below;
[2] In the Header Info dialog box, select TIFF from the File Type dropdown list and click OK. Afterward, the icon for 2003 changes, as shown below;
[3] In the ENVI main menu, select File->Save File As->TIFF/GEOTIFF, choose the output location in the dialog box, click OK to finish.
Thursday, February 29, 2024
Matlab: a simple approach for classifing two kinds of types on the image
It works well on small areas (here at the Plot level) and only with two types in the image that have significant color differences. File.
I added a loop to minimize the effect of the non-Rgeion of Interest on the binzrization process. 2nd. 3rd.
The conditions for applying the binary process are quite stringent. It's important to ensure that the image to be processed contains fairly typical features of the terrain colors and in appropriate quantities. Only then is it the right image to use, as this minimizes the area of invalid regions. 4th.
Wednesday, February 28, 2024
Matlab: Convert RGB to HSV/XYZ/LAB/Ycbcr/NTSC
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | % Created by LI Xu % Version 1.0 % February 22, 2024 % If you have any question about this code, % please do not hesitate to contact me via E-mail: % jeremy456@163.com % Blog: % http://blog.sciencenet.cn/u/lixujeremy clear; clc; timebegin=tic; cur_data=date; cur_time=fix(clock); str1=sprintf('%s %.2d:%.2d:%.2d', cur_data, cur_time(4), cur_time(5), cur_time(6)); fprintf('Time Begin: '); fprintf(str1); fprintf('\n'); filename='wheat'; % Source Directory SouDir='input'; % Destination Directory DesDir='output'; files=dir(SouDir); files=files(3:end); for ii=1:numel(files) % construct the input file path filepath=fullfile(SouDir, files(ii).name); [image, geo]=readgeoraster(filepath); image=double(image); try info=geotiffinfo(filepath); catch info=georasterinfo(filepath); end Num_bands=size(image, 3); if Num_bands==3 RGB=image; else RGB=zeros(size(image, 1), size(image, 2), 3); RGB(:, :, 1)=image(:, :, 4); RGB(:, :, 2)=image(:, :, 2); RGB(:, :, 3)=image(:, :, 1); end % Normalise the RGB bands [0, 255] RGB=GenNormalise(RGB); % https://www.mathworks.com/help/images/understanding-color-spaces-and-color-space-conversion.html xyz=rgb2xyz(RGB); lab=rgb2lab(RGB); ycbcr=rgb2ycbcr(RGB); ntsc=rgb2ntsc(RGB); HSV=rgb2hsv(RGB); % ExG = 2 * G - R - B ExG=2*RGB(:, :, 2)-RGB(:, :, 1)-RGB(:, :, 3); otpath=strsplit(files(ii).name, '_'); otpath=otpath(2:end); otpath=strjoin(otpath, '_'); otpath_rgb=[filename, '_rgb_', otpath]; otpath_hsv=[filename, '_hsv_', otpath]; otpath_xyz=[filename, '_xyz_', otpath]; otpath_lab=[filename, '_lab_', otpath]; otpath_ycbcr=[filename, '_ycbcr_', otpath]; otpath_ntsc=[filename, '_ntsc_', otpath]; otpath_exg=[filename, '_exG_', otpath]; otpath_rgb=fullfile(DesDir, otpath_rgb); otpath_hsv=fullfile(DesDir, otpath_hsv); otpath_xyz=fullfile(DesDir, otpath_xyz); otpath_lab=fullfile(DesDir, otpath_lab); otpath_ycbcr=fullfile(DesDir, otpath_ycbcr); otpath_ntsc=fullfile(DesDir, otpath_ntsc); otpath_exg=fullfile(DesDir, otpath_exg); try geotiffwrite(otpath_rgb, RGB, geo); geotiffwrite(otpath_hsv, HSV, geo); geotiffwrite(otpath_xyz, xyz, geo); geotiffwrite(otpath_lab, lab, geo); geotiffwrite(otpath_ycbcr, ycbcr, geo); geotiffwrite(otpath_ntsc, ntsc, geo); geotiffwrite(otpath_exg, ExG, geo); catch strcmd=['gdalinfo ', filepath]; [~, cmdout]=system(strcmd); epsg=extractBetween(cmdout, "EPSG:"," got from GeoTIFF keys"); epsg=epsg{1}; % geotiffwrite(otpath, uint8(class_imag), geo, 'GeoKeyDirectoryTag', info.GeoTIFFTags.GeoKeyDirectoryTag); geotiffwrite(otpath_rgb, RGB, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_hsv, HSV, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_xyz, xyz, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_lab, lab, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_ycbcr, ycbcr, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_ntsc, ntsc, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); geotiffwrite(otpath_exg, ExG, geo, 'CoordRefSysCode', ['EPSG:', epsg], 'TiffType', 'bigtiff'); end disp(['[', num2str(ii), '/', num2str(numel(files)), ']~', files(ii).name]); end fprintf('Time Begin: '); fprintf(str1); fprintf('\n'); cur_data=date; cur_time=fix(clock); str2=sprintf('%s %.2d:%.2d:%.2d', cur_data, cur_time(4), cur_time(5), cur_time(6)); fprintf('Time End: '); disp(str2); timespan=toc(timebegin); fprintf('Time Span: %.4f s\n', timespan); disp('***********************************************'); function output=GenNormalise(input) output=input*0; for ii=1:size(input, 3) image=input(:, :, ii); % red_normalized = (red - red.min()) / (red.max() - red.min()) * 255 aa=image(:); image_normalized=(image-min(aa))./(max(aa)-min(aa))*255.0; output(:, :, ii)=image_normalized; end end |
Matlab: Decision Tree Tool for Image
This is a simple tool of decison tree for the image analysis.
It can export the compared image and the ruleset file at once. File.
Monday, February 26, 2024
Subscribe to:
Posts (Atom)