dslreports logo
 
    All Forums Hot Topics Gallery
spc
uniqs
34
fartness (banned)
Donald Trump 2016
join:2003-03-25
Look Outside

fartness (banned) to EGeezer

Member

to EGeezer

Re: More fast food employee stupidity

I don't know much about EXIF data and how it can be extracted or deleted from pictures. Any good reading or brief explanation?

If I take a picture and it's 1600x1200 resolution and has the EXIF data, but I use a program to size it down to 800x600, will that strip the EXIF data?

My phone doesn't have a data plan (Blackberry Bold 9000 from ATT), so if I take a picture, how does it add this data?

Juggernaut
Irreverent or irrelevant?
Premium Member
join:2006-09-05
Kelowna, BC

Juggernaut

Premium Member

With the on-board GPS and/or the cell towers.
dave
Premium Member
join:2000-05-04
not in ohio

1 recommendation

dave to fartness

Premium Member

to fartness
said by fartness:

If I take a picture and it's 1600x1200 resolution and has the EXIF data, but I use a program to size it down to 800x600, will that strip the EXIF data?

It depends on the program. To my mind, a sensible default is to transfer the still-relevant EXIF data: after all, you told the program to "resize", not "throw away non-image info". But the same sensible program ought to allow you to explicitly discard metadata.

On the other hand, Windows Explorer (in Win7 at least) allows you to throw away EXIF data. Right-click, property sheet, details, 'discard personal details'. I haven't tested this out with GPS, for lack of a suitable test image.

NetFixer
From My Cold Dead Hands
Premium Member
join:2004-06-24
The Boro
Netgear CM500
Pace 5268AC
TRENDnet TEW-829DRU

4 edits

NetFixer to fartness

Premium Member

to fartness
said by fartness:

I don't know much about EXIF data and how it can be extracted or deleted from pictures. Any good reading or brief explanation?

If I take a picture and it's 1600x1200 resolution and has the EXIF data, but I use a program to size it down to 800x600, will that strip the EXIF data?

My phone doesn't have a data plan (Blackberry Bold 9000 from ATT), so if I take a picture, how does it add this data?

Whether or not any specific graphics manipulation program will strip the EXIF data when resizing the image will depend on how that particular program was designed (and/or how you save the resized image). Most graphics programs have a "Save for Web" feature that does strip the EXIF info.

Shown below are some samples that were modified using IrfanView to illustrate just that scenario (the original 1600x1200 image has EXIF data, but not GPS data):


Original 1600x1200 image (with EXIF)



Original image EXIF data



Image resized to 800x600 (with EXIF)



Resized image EXIF data



Resized image using Save for Web



The Save for Web image has no EXIF data


I am not familiar with your Blackberry Bold 9000 phone, but GPS data is done by communicating with GPS satellites, and no phone or WiFi connection is required. EXIF data (with or without GPS data) is simply a function of the camera and requires no on-line connectivity to anything. Whether your Blackberry Bold 9000 even has EXIF capability is unknown to me (but you should be able to easily find out by taking a picture and using a graphic display program such as IrfanView to look at it).
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

TheMG to fartness

Premium Member

to fartness
said by fartness:

If I take a picture and it's 1600x1200 resolution and has the EXIF data, but I use a program to size it down to 800x600, will that strip the EXIF data?

It may or may not, depending on what program you use and how it is configured.

The program that I use for converting photos, Irfanview, gives you the option of keeping or removing the original EXIF data. With an optional plugin it also allows you to change, add, or selectively remove some of the information.
said by fartness:

My phone doesn't have a data plan (Blackberry Bold 9000 from ATT), so if I take a picture, how does it add this data?

It uses coordinates from its own internal GPS receiver and inserts the coordinated into the EXIF data in the image. No cellular data plan or internet connectivity required.

NormanS
I gave her time to steal my mind away
MVM
join:2001-02-14
San Jose, CA
TP-Link TD-8616
Asus RT-AC66U B1
Netgear FR114P

NormanS to fartness

MVM

to fartness
Using IrfanView:

IrfanView menu.


I can find the following:
xif-olymp.txt
1638 bytes
Olympus digital camera.

xif-moto_rzr.txt
809 bytes
Motorola phone.

xif-huawei.txt
937 bytes
Huawei phone.


The camera is very old, and has no GPS configuration menus. Both phones had GPS options set to "911 only".

I have not edited the images, so can't address whether edits alter the EXIF data.

An Internet search will find numerous standalone EXIF readers. Photo editing software should also.