Displaying blobs

[DustinWiersma2]

Hello All,

I have a mobile project running using ArcGIS mobile for Windows.  The project is being used by Trimble Junos - in order to allow the Trimbles to collect more than one picture in one location, I named the fields in the DB "Picture_1", ect.  This works great as it prompts the camera to open in the Trimble or add a photo that is already stored on the Trimble.  The problem I am having is adding the pictures directly into a Flex map so the Flex map is populated with data "live" from the field.  My current work flow is:

-Copy the feature class to a personal geodatabase (since it is a Microsoft Access database)
-Run a script that extracts the blobs as jpegs to a folder
-Have the Flex map call to that folder to display the images

The problem with this is that the data does not feed live to the Flex map.  Any ideas?
Thanks!

-Dustin Wiersma, GIS Analyst

[BjornSvensson]

I have a mobile project running using ArcGIS mobile for Windows...pictures

That won't work because the server doesn't return BLOBs using the REST API (which is how Flex and other Web APIs connect to ArcGIS Server).

Instead of storing the images in BLOBs, you would need to use attachments (or files in folders like your batch script is doing now).  I don't know enough of the "trimble/mobile" aspect how to make that happen though...
http://resources.arcgis.com/en/help/main/10.1/index.html#//01m90000000r000000

[DustinWiersma2]

Thanks for the reply!  That is interesting about the rest point and blobs.  Unfortunately, the Trimbles do not use the attachment table for this project - other mobile projects do, such as mobile projects using the esri ArcGIS app.  For this project I need to have multiple photos for a single point, otherwise I could just use a field as a type raster.  So it sounds like I may need to develop a script that automates my current workflow.

[RhettZufelt]

I don't do mobile, but FLEX has issues accessing a local folder.  You normally need to set up a virtual directory on your server that points to the folder you are saving the jpegs in.  You can then access them using the URL in the flex viewer.

R_

[DustinWiersma2]

Rhett,
Thanks for the reply!  That will be the work flow I will try to automate - have a script that extracts the blobs to jpegs in a folder on the server and have the Flex map point to that folder.

[RhettZufelt]

Dustin,

I have a similar workflow, with photos stored in BLOB fields and one to potentially many photos per feature.  The attachemnts feature doesn't really support 1:many so I have a python script that extracts the jpeg photos from the blob and saves them in a folder.  As it is writing the blobs, I capture the path and filename that I am saving them to (as well as my feature ID) and append to a list, then at the end of my script, I insertCursor the list to populate a FGDB table.  Now I not only have the jpeg stored local in a folder, I also have a ready-made table with all my paths ready to join/calculate to the feature class data that can be used for my link field.

Of course, I had to make a virtual directory on the server pointing to the folder I saved all my jpegs in, then had to go into IIS and, for that virtual folder, allow directory browsing as I often have many photos per site (if just one photo, my "path" actually points to the jpeg file, if more than one, it points to the folder.

This was kind of cluttery, especially for the sites with multiple photos, as IE doesn't give thumbnail views, so, all you see is a list of the somewhat cryptic filenames, and need to click on each photo to view it.

So, I took it one step farther.  After my python script extracts and saves the jpegs from the BOLBs, writes the "lookup table", joins/calculates the URL info to my feature class, it then runs a slightly modified version of pyGallery.  This creates a gallery for my photos similar to ( http://pygallery.sourceforge.net/samples/ ).  So now, if there is one photo, my popup says "Click for Photo", and it takes you direclty to the image viewed in a browser.  If there are more than one image, it says "Click for Photos", and if you click, it will take you to the index/thumbnail gallery page for that feature, with all the photos.

So far, not only the best way I've came up with for BLOBs, but also for one:many photos in Flex.

In case this gives you some ideas,

R_

[DustinWiersma2]

Wow, that is quite the work flow.  That is exactly what I need to do.  Do you have the script written so it runs automatically on a time schedule?

[RhettZufelt]

Dustin,

With python and ArcGIS, I have found that it is normally best to execute all python scripts (at least scheduled ones) from a batch file. this way, once it is done with that particular script, since it was spawned in a separate python instance, it will then relsease all the "cryptic" locks it puts on the data and can move on to the next script.

So, if I have many scripts to run, I make one python script with a bunch of os.system(batchfilename) calls, will run the script, close the process, and move on.

each batch file is similar to :

cd C:\Python27\ArcGIS10.1

Python C:\arcgisserver\python\finish.py

pause

Exit

Which sets the path to the python version I want to use, then executes the finish.py script, then exits when done.

To schedule, I just use the windows scheduled tasks (task scheduler in Win 7) to run it on a nightly/weekly basis.

The "pause" in red I normally REM out, but is nice when developing so it doesn't just close the window down if it encounters an error.


R_

Instead of the windows scheduler, I have used pyCRON in the past as well. Works like CRON on 'IX systems.

[AlexSanders]

Rhett,

Is there any way you can share your python work flow for extracting the BLOB fields from a database to disk?

Alex

Dustin,

I have a similar workflow, with photos stored in BLOB fields and one to potentially many photos per feature.  The attachemnts feature doesn't really support 1:many so I have a python script that extracts the jpeg photos from the blob and saves them in a folder.  As it is writing the blobs, I capture the path and filename that I am saving them to (as well as my feature ID) and append to a list, then at the end of my script, I insertCursor the list to populate a FGDB table.  Now I not only have the jpeg stored local in a folder, I also have a ready-made table with all my paths ready to join/calculate to the feature class data that can be used for my link field.

Of course, I had to make a virtual directory on the server pointing to the folder I saved all my jpegs in, then had to go into IIS and, for that virtual folder, allow directory browsing as I often have many photos per site (if just one photo, my "path" actually points to the jpeg file, if more than one, it points to the folder.

This was kind of cluttery, especially for the sites with multiple photos, as IE doesn't give thumbnail views, so, all you see is a list of the somewhat cryptic filenames, and need to click on each photo to view it.

So, I took it one step farther.  After my python script extracts and saves the jpegs from the BOLBs, writes the "lookup table", joins/calculates the URL info to my feature class, it then runs a slightly modified version of pyGallery.  This creates a gallery for my photos similar to ( http://pygallery.sourceforge.net/samples/ ).  So now, if there is one photo, my popup says "Click for Photo", and it takes you direclty to the image viewed in a browser.  If there are more than one image, it says "Click for Photos", and if you click, it will take you to the index/thumbnail gallery page for that feature, with all the photos.

So far, not only the best way I've came up with for BLOBs, but also for one:many photos in Flex.

In case this gives you some ideas,

R_

[RhettZufelt · Accepted solution]

Stuart/Alex,

Here are the nuts and bolts of it:

This is using the python that comes with 10.1 (v2.7.2).

import arcpy, os from arcpy import da  inTable = "C:\\Connection to RCES_P.sde\\SIS_ADM.IMAGES"  #  table with identifier (SITE_CODE), imageID number (IMAGE_ID), and photo in BLOB field (PHOTO)  savepath = "\\\\mcflight01\\WebImages"            #  initial path to save images/sub folders   with da.SearchCursor(inTable,['SITE_CODE','IMAGE_ID','PHOTO']) as cursor:    for row in cursor:          SITE_CODE = str(row[0])   # gets feature identifier from table  (SITE_CODE) as string          Fid = str(int(row[1]))    # gets ImageID from table (IMAGE_ID) as string without decimal point          binaryRep = row[2]        #  get photo from BLOB field as binaryRep variable          filename = (SITE_CODE.replace(':','_')).replace('/','')  + "_" + Fid + ".jpg"  # appends site_code to filename replacing : and /'s          folder = savepath + os.sep + SITE_CODE.replace(':','_')                        # appends site_code to folder replacing : with _            if binaryRep:              if not os.path.exists(folder):                 os.system("mkdir " + '"' + folder + '"')                           # if doesn't already exist, make folder using folder variable              open(folder + os.sep  + filename, 'wb').write(binaryRep.tobytes())    # this actually saves the BLOB stored in binaryRep to filename variable           del binaryRep del row

R_