Subject Re: Closing an image on a form
From Mervyn Bick <invalid@invalid.invalid>
Date Sun, 2 May 2021 17:55:59 +0200
Newsgroups dbase.getting-started
Attachment(s) extract_exif.prg

On 2021/05/02 12:09, roy price wrote:
> Hello Mervyn,
 > I did use your (simpler) code to relate the filenames from the disk directory to the image on the Form.
 > I am now wondering if a similar code would extract the date-taken from the same filename. I've tried but failed.
 > Regards
 > Roy Price
 >

The date and time that the photo was taken may (not all cameras are
fully house-trained) be in the EXIF meta data in the photo.

I looked at the EXIF specification and data in some of my own photos and
decided that writing code for this task was above my pay-grade. :-(

There are several activeX controls that are available to get this
information but they all cost money.

As my middle name is Scrooge I looked for something free even if it
meant going the scenic route to get there.

I found Exiftool which is free and which has a command line option.
I've built a little program around this.  You will, of course, need to
fetch a copy of Exiftool.  I used the alternative installer from
https://oliverbetz.de/pages/Artikel/ExifTool-for-Windows

Not all photos have the information saved so this may not be of much help.

If it works you will wind up with a table exif_dates.dbf which will have
the names and timestamps of those photos which do have the timestamp in
the EXIF data.

You will need to edit the values for cDir and cTextFile as appropriate.

Mervyn.







cDir = "d:\pictures"
cTextFile = "d:\examples\plus2019\EXIF_dates.txt"

if file(cTextFile)
  new File().delete(cTextFile)
endif
f = new file()
f.create('ex_exif.bat')
f.puts([exiftool -p "$filename has date $dateTimeOriginal" -q -f  ]+cDir+[ >> ]+cTextFile)
f.close()
if (type("WinExec") # "FP")
      extern CWORD WinExec(CSTRING, CUINT) Kernel32
endIf
SW_HIDE = 0
WinExec('ex_exif.bat'+Chr(0), SW_HIDE)

inkey(2) //Wait for text file to be written and closed.

if file("exif_dates.dbf")
   drop table exif_dates
endif

create table exif_dates (image_name char(20),exif_timestamp timestamp)
q = new query()
q.sql = 'select * from exif_dates'
q.active = true
f = new file()
f.open(cTextFile)
do while not f.eof()
  cRead = f.gets(10000)
  if ':'$cRead
     q.rowset.beginAppend()
     q.rowset.fields[1].value = substr(cRead,1,at(' ',cRead)-1)
     q.rowset.fields[2].value = substr(cRead,at('date',cRead)+5)
     q.rowset.save()
  endif
enddo
f.close()
q.active = false