How can a b/w photo's thumbnail be in colours?

[Curt]

Obviously this photo began life as a colour picture, and only then was converted into black & white. But it is a mystery to me how Explorer and several photo editors can display the thumbnail in colours. Of course the photo is b&w when I open it, but even when copied, the new thumbnail is still in colours. I wonder if a photo somehow is carrying a thumbnail photo of itself? I have never seen this before - but of course I very seldom have any black & white pictures. Actually, in this case as in most cases, I think I would prefer the colourful "orange" version ;-)
 
Edited:
I have not edited this photo; it was downloaded in black & white.

-------------

EXIF

---- Image Information ---------------------------------------------------------
Filename:                       001_Citroën DS.jpg
File size:                      665 KB (681 437 bytes)
Dimensions:                     2376 x 1800
Bit depth:                      24
Created:                        8. oktober 2005 18:57:46
Changed:                        16. juli 2012 00:22:33

---- Description ---------------------------------------------------------------
Title                           OLYMPUS DIGITAL CAMERA        

---- Picture Taking Conditions -------------------------------------------------
Audio note                      No
Camera data                     Yes
Text information                Yes
Created                         8. oktober 2005 18:57:46
Digitized                       8. oktober 2005 18:57:46
Modified                        8. oktober 2005 18:57:46
Flash                           No
Exposure time                   1/250 s
Aperture                        3.2
Max. aperture                   3.25
Focal length                    38.10 mm
Focal length (EQ35mm)           250 mm
ISO                             200
Digital zoom ratio              0.00
Exposure bias                   0
Metering mode                   Pattern
Exposure mode                   Auto exposure
White balance                   Automatic
Exposure program                Creative program (biased toward depth of field)
Orientation                     Normal
Sharpness                       Normal
Contrast                        Normal
Saturation                      Normal
Gain control                    Low gain up
Scene capture type              Standard
Camera Make                     OLYMPUS CORPORATION
Model                           C750UZ
Software                        v753u2-86
Compression                     JFIF Compression
Color representation            YCbCR
DPI                             72.00
Exif version                    2.20
Flashpix version                1.00
Colorspace                      sRGB
Flash - detailed                Flash did not fire, Compulsory flash suppression
File source                     Digital camera
Scene type                      A directly photographed image
Custom image processing         Normal process
Subject distance range          Distant view
Compression quality             SQ
Firmware                        SX753
Keywords                        No
Digital signature               No

-------------

The thumbnails in "Large icons"-view In Explorer (big b/w pop-up thumbnail created by QTTabbar):



-------------
As seen in Zoner 14 PRO photo editor (the "orange" photos are the thumbnails of 3 b&w photos):



-------------
The actual photo (click to enlarge):

How can a b/w photo's thumbnail be in colours?

[nite_monkey]

I actually have a picture on my computer that is the exact opposite. It was a black and white photo, and if I remember right, the exact steps I took were, 1. right click on the image in my browser and click copy, 2. paste into Photoshop and colorize it, and 3. save the image. Now the thumbnail in windows explorer is black and white, while the actual image is in color. I have never had this happen any other time.

(on a side note, your computer spells October weird. I'm from America, and only speak english, so if it is a foreign thing, that would explain it.)

[Curt]

-that can happen if you save it with the same filename.
In this case I have done nothing to the original which was downloaded in b&w.

(On a side-note, English is not my second language, but a foreign language.)

[nite_monkey]

The file was never originality saved on my computer though. It was basically a fresh image from Photoshop.

[Renegade]

The metadata inside of some image formats contains a thumbnail (or stamp). This information is entirely separate and distinct from the actual image itself, but is formed when the photograph is taken.

Not all editors deal with stamps (thumbnails) or not all editors deal with them properly.

When I wrote the Super Simple Photo Resizer, I came across this issue, and instead of simply not dealing with it, in at least some case (IIRC) I delete the stamp/thumbnail from the image file entirely. There are very good reasons to do this...

Imagine you're at home, getting out of the shower, and your spouse snaps a photo of you. While you don't want to post full frontal nudity of yourself, perhaps the facial expression is really funny, and you want to share that. So, you crop the photo and email or upload it...

Now, if the software didn't erase the stamp, you've just sent that original stamp of your naked body around. Not good. And probably not what you'd intended to do.

Anyways, that's a bit long for the simple explanation. -- Stamps and image data are not the same.

[Curt]

-thank you, Renegade.

so Stamps, Meta data and EXIF are two/three different things?
The coloured thumbnail did not go away when I deleted all EXIF data, and renamed the photo.
How do I "find" the stamp?
 

[Renegade]

Oh - don't forget to check the "thumbs.db" file as it can contain cached data. You can safely delete that. If you've deleted the EXIF data, then the stamp is likely gone, but still in the thumbs.db file.

(That sounds like the issue - though I'm certain there are other ways for the wonderful world of computing to melt our minds! )

[jgpaiva]

Imagine you're at home, getting out of the shower, and your spouse snaps a photo of you. While you don't want to post full frontal nudity of yourself, perhaps the facial expression is really funny, and you want to share that. So, you crop the photo and email or upload it...

Now, if the software didn't erase the stamp, you've just sent that original stamp of your naked body around. Not good. And probably not what you'd intended to do.

-Renegade (July 15, 2012, 11:52 PM)

Thanks a lot for that explanation, I had no idea it could happen!

[40hz]

Perhaps this might explain things?

All is revealed here

 

[Curt]

Perhaps this might explain things?

All is revealed here

[ Invalid Attachment ]

-40hz (July 16, 2012, 07:56 PM)

  -thank you for making your post a perfect start of my day, 40hz 

[40hz]

Perhaps this might explain things?

-40hz (July 16, 2012, 07:56 PM)

  -thank you for making your post a perfect start of my day, 40hz   (see attachment in previous post)

-Curt (July 17, 2012, 03:22 AM)

 

[superboyac]

Perhaps this might explain things?

-40hz (July 16, 2012, 07:56 PM)

  -thank you for making your post a perfect start of my day, 40hz   (see attachment in previous post)

-Curt (July 17, 2012, 03:22 AM)

(see attachment in previous post)
 

-40hz (July 17, 2012, 08:21 AM)

That was classic!  Made my day as well.  Man, I used to read that strip every day.

[J-Mac]

Me three!!  ^

Thanks for that strip 40hz - makes perfect sense to me!

Jim

[mwb1100]

Imagine you're at home, getting out of the shower, and your spouse snaps a photo of you. While you don't want to post full frontal nudity of yourself, perhaps the facial expression is really funny, and you want to share that. So, you crop the photo and email or upload it...

Now, if the software didn't erase the stamp, you've just sent that original stamp of your naked body around. Not good. And probably not what you'd intended to do.

-Renegade (July 15, 2012, 11:52 PM)

Kind of like what happened to Cat Schwartz from the old TechTV show:

NSFW

http://www.welcometo...ld.com/cat-schwartz/

[Renegade]

Imagine you're at home, getting out of the shower, and your spouse snaps a photo of you. While you don't want to post full frontal nudity of yourself, perhaps the facial expression is really funny, and you want to share that. So, you crop the photo and email or upload it...

Now, if the software didn't erase the stamp, you've just sent that original stamp of your naked body around. Not good. And probably not what you'd intended to do.

-Renegade (July 15, 2012, 11:52 PM)

Kind of like what happened to Cat Schwartz from the old TechTV show:

-mwb1100 (July 19, 2012, 01:13 AM)

Exactly~!

[Curt]

Thanks, mwb1100, the Cat Schwartz example was a perfect answer to my question
-well, even a beautiful answer...