Taking the Grunt out of Geotags

Here's a matlab script to automatically compile all geo-tagged images from a directory and all its subdirectories into a Google Earth kml file showing positions and thumbnails

	close all;clear all;clc
	addpath('/path/where/googleearth/toolbox/is')
	% get main directory (Projects directory)
	pathFolder=uigetdir();
	% get list of subfolders
	d = dir(pathFolder);
	isub = [d(:).isdir];
	nameFolds = {d(isub).name}';
	nameFolds(ismember(nameFolds,{'.','..'})) = [];
	% prompt user to select which subfolders to process
	[s,v] = listdlg('PromptString','Select folders:',...
	'SelectionMode','multiple',...
	'ListString',nameFolds);
	% use only those directories
	directories=char(nameFolds(s));
	for md=1:size(directories,1)
	% get list of subfolders
	d = dir(strtrim([pathFolder,filesep,directories(md,:)]));
	isub = [d(:).isdir];
	nameFolds = {d(isub).name}';
	nameFolds(ismember(nameFolds,{'.','..'})) = [];
	subdirectories{md}=char(nameFolds);
	end
	mattime=[]; timestring=[]; lat=[]; lon=[]; filenames={};
	direc=[];
	counter=0;
	for dd=1:size(directories,1)
	for sd=1:size(subdirectories{dd},1)
	if isempty(strmatch(strtrim(subdirectories{dd}(sd,:)),'dng')) &&...
	isempty(strmatch(strtrim(subdirectories{dd}(sd,:)),'crw'))
	files1=ReadImDir(strtrim([pathFolder,filesep,strtrim(directories(dd,:)),...
	filesep,strtrim(subdirectories{dd}(sd,:))]),'JPG');
	files2=ReadImDir(strtrim([pathFolder,filesep,strtrim(directories(dd,:)),...
	filesep,strtrim(subdirectories{dd}(sd,:))]),'jpg');
	files=char(files1,files2); %,files3
	for k=1:size(files,1)
	in=strtrim([pathFolder,filesep,strtrim(directories(dd,:)),filesep,strtrim(subdirectories{dd}(sd,:)),...
	filesep,strtrim(files(k,:))]);
	if isempty(regexp(in,'ppm.jpg', 'once'))
	counter=counter+1;
	filenames{counter}=in;
	[stat,res]=system(['exiftool -h "',in,'"']);
	latstr=res(regexp(res,'>GPS Latitude<')+22:regexp(res,'>GPS Latitude<')+41);
	if ~isempty(latstr)
	deg=str2double(strtrim(latstr(1:2)));
	mins=str2double(strtrim(latstr(8:9)));
	secs=str2double(strtrim(latstr(16:end)));
	lat=[lat; deg+ mins/60 + secs/3600];
	lonstr=res(regexp(res,'>GPS Longitude<')+22:regexp(res,'>GPS Longitude<')+42);
	deg=str2double(strtrim(lonstr(2:4)));
	mins=str2double(strtrim(lonstr(10:11)));
	secs=str2double(strtrim(lonstr(17:end)));
	lon=[lon; deg+ mins/60 + secs/3600];
	timestr=res(regexp(res,'>GPS Date/Time<')+23:regexp(res,'>GPS Date/Time<')+41);
	y=str2double(timestr(1:4)); m=str2double(timestr(6:7)); d=str2double(timestr(9:10));
	H=str2double(timestr(12:13)); M=str2double(timestr(15:16)); S=str2double(timestr(18:19));
	if S==0
	S=S+1;
	end
	mattime=[mattime;datenum([y,m,d,H,M,S])];
	timestring=[timestring;datestr(datenum([y,m,d,H,M,S]))];
	direc=[direc;dd];
	else
	lat=[lat;NaN]; lon=[lon;NaN];
	timestr=res(regexp(res,'>Create Date<')+21:regexp(res,'>Create Date<')+39);
	y=str2double(timestr(1:4)); m=str2double(timestr(6:7)); d=str2double(timestr(9:10));
	H=str2double(timestr(12:13)); M=str2double(timestr(15:16)); S=str2double(timestr(18:19));
	if y==2012
	y=y+1;
	end
	if S==0
	S=S+1;
	end
	mattime=[mattime;datenum([y,m,d,H,M,S])];
	timestring=[timestring;datestr(datenum([y,m,d,H,M,S]))];
	direc=[direc;dd];
	end
	end % if not ppm.jpg
	end %k
	end % if not dng or crw
	end %sd
	end %dd
	thumbfiles=cell(size(filenames));
	for i=1:length(lat)
	thumbfiles{i}=[filenames{i},'_thumb.jpg'];
	end
	kmlStr=cell(1,length(lat));
	for i=1:length(lat)
	system(['exiftool -b -ThumbnailImage ',filenames{i},' > ',thumbfiles{i}])
	kmlStr{i} = ge_point_new(-lon(i),lat(i),0,...
	'description',['<a href="',filenames{i},'">link to file</a>'] ,...
	'iconURL',thumbfiles{i},...
	'name',filenames{i}(regexp(filenames{i},'IMG'):end));
	end
	tmp=[];
	for i=1:length(lat)
	tmp=[tmp,eval(['kmlStr{',num2str(i),'}'])];
	end
	ge_output('points.kml',...
	ge_folder('points',tmp));
	system(['google-earth "',pwd,filesep,'points.kml" &'])
	save('photo_res','mattime','lat','lon','direc','timestring','filenames','directories')

view raw geophotos2kml.m hosted with ❤ by GitHub

Like most of my matlab scripts, it's essentially just a wrapper for a system command. It requires exiftool for the thumbnail creation (available on both *nix and for Windows). It also needs the (free) Google Earth toolbox for Matlab.

Right now it's just set up for JPG/jpg files, but could easily be modified or extended. As well as the kml file (Google Earth will launch as soon as the script is finished) it will save a matlab format file contining the lats, longs, times and filenames.

Outputs look a little like this (a selection of over 30,000 photos taken in Grand Canyon)