Photograph transfer problem

[#1]

Transferred some holiday photos to the computer from a Compact Flash card, made a few changes to them and then reloaded them back on to the card, however the camera did not recognise them and I just got the message, 'no image'.
The reason I wish to do this is fairly detailed and not really relevant to the above.
All the images are jpegs and clearly transfer to the CF card from the computer.
Anyone any ideas ?

[#2]

Only thing I can think of, is that the image stored, orignally, by the camera, is not .jpg format.... therefore when you return images in .jpg format, they will not be recognised by the camera as it will only recognise it`s own format, ( whatever that may be )...
Also, when you "manipulate" a pic on external progs, you change the characteristics of it... e.g. if you only "improve" the contrast slightly you will reduce the size of the file... so this may well be seen as "corruption" by the camera when it is returned to the camera, therefore it "plays safe"... and says "no image"...

[#3]

This http://www.techlore.com/blog/entry/23265/Putting-Modified-Photos-Back-Onto-Your-SD-Card/ might help

[#4]

Thanks for the responses and the link.
My wife has a Canon IXUS which takes a sd card, I had no trouble changing the photos and downloading them back to card and the camera could read them, however my own Canon SLR uses a compact flash card but no way can the camera see the downloaded photos, as stated in the article some cameras may not be able to see photos downloaded on a card.
I Did try downloading my photos to the SD card in the hope my wife's camera could see them but no luck.

[#5]

Might be worth looking at the exif information of the original and edited images http://en.wikipedia.org/wiki/Exchangeable_image_file_format

[#6]

My thoughts too!

[#7]

A point I had forgotten was mentioned in the article.... that the "file name" has changed, so the camera will not recognise it...
original pic   file name.... (e.g) img00001   downloaded and "fixed" by you, now becomes 001.jpg try changing the file name back to img0001 ( before saving it to the flash card ) ... and see if the camera accepts it....

[#8]

A thought came to me, in the middle of the night..... ( actually, about 3 a.m.   )
Start > Control Panel >  Hardware & Sounds > Autoplay > Pictures ....... drop down menu.... select "Open Folders to view".. you should see the pic files on the card with the camera number as the file name....   Save all the original pics in a NEW FOLDER on your desktop ...... then erase those on the card...... do your "adjustments" and "Save As... "  in a sub- folder  ( on desktop  ? ? ? )  then when  finished, you should be able to copy the new ones back to the camera, without changing the file name.... and should be able to read them on the camera... ( hopefully ! ) ..

[#9]

Thanks for the ideas, will have a play around with this later and let you know how I get on 

[#10]

Generally speaking... the firmware inside a camera is heavily optimised for writing streams of bytes to the flash memory at speed - that continuous shooting is megabits per second. As a consequence, the camera's firmware makes assumptions about the byte format of the photo file. These shortcuts are not a problem when what the camera gets is what the camera expects, but when there's something different about the data, a photoshopped photo for example, the firmware says uh oh, and decaleres not an image.
For example, the image may have different X Y dimensions or dpi resolution, use a slightly different set of compression table rules, format numeric values in a perculiar way, or have the embedded JPEG thumbnail with a different offset. Sometimes there is no Exif data at all, just a JFIF marker! Meanwhile, your computer/tablet/TV when displaying a JPEG image is doing a load of 'what-if-then-do-something-else' processes. As no one JPEG image is formatted exactly the same as the other, to display custom images inside a digital camera, you need a custom image that has an identical digital signature to a photo taken by the camera.
Try setting the width and height to match those taken by the camera. You might get lucky.

Quote

Saving an image file will fundimentally change the digital metadata even though the image remains the same. Here, the first few bytes of an image changes when a photo is imported into a photo editor and is then saved again. Often the image processor in the camera lacks the skill to decode the metadata in the new format. Camera file: ÿØÿà..JFIF.¢...(...........1.......ª...2.......Æ...............i‡.....Ü...¸...Canon.Canon EOS 20D.2012:02:0516:38:10.2012:02:0516:38:10.*è......;ë..............#.......................... ................-â†éŠ[Åi±×.^1UÔÀ­.ŠÒ¢­H...................................................... ..........hô÷T.LÊ............................................................................ Post Photoshop save file: ÿØÿà..JFIF.....H.H..ÿâ.0ICC_PROFILE......0ADBE....mntrRGB XYZ..........acspAPPL....none........ ...Ó-ADBE................................................cprt...ü...2desc...0...kwtpt...œ....bk ..Ô....bTRC...ä....rXYZ...ô....gXYZ........bXYZ........text....Copyright 1999 Adobe Systems Inc orporated...desc........Adobe RGB (1998)..............Photoshop 3.0.....%.........t..«ÁÅW«o….ªø

[#11]

An excellent explanation of my para 2 in my first reply 

[#12]

Spent ages on this but without success so it might be helpful to explain why I am trying to do this.
The idea was to download the altered photographs to the camera and using the appropriate connector transfer these photos to a first generation ipad.
Now I have already done this with my wife's camera without any problems it's the ones I have took on a Canon SLR that are proving to be the headache, it seems the ipad does not have enough power to transfer the photos direct from a card but if connected to the camera it uses the cameras power.
I Have also tried a usb stick but get some odd message on the ipad there is not enough power to use the device. I am now wondering if the usb stick would work through a powered hub ?

[#13]

would it work if the Ipad was plugged in and charging at the time of the transfer ?
Take a couple of pics on an empty card,.... doesn`t matter what... then follow my Start>control panel> instructions and see if that works....

[#14]

This is the connector I am using at the moment so as you can see it could take a usb lead for power and a card at the same time but I would be a bit bothered about shorting something out.
http://www.ebay.co.uk/itm/5in-1-USB-SD-TF-Card-Reader-Adapter-Camera-Connection-Kit-for-iPad1-ipad2-...

[#15]

When "returning" pics to the card... (with the original camera file number) have you done this....

Quote

THERE MUST BE A FOLDER TITLED 'DCIM' IN THE ROOT DIRECTORY OF THE SD CARD OR USB. MOST CAMERAS CREATE ONE AUTOMATICALLY, BUT IF YOU CAMERA DOESNT YOU MUST CREATE ONE ON YOUR CARD FIRST.

If your camera numbers are DCIM 000001 ( for example) they must be returned to the camera with that "type" of number in the "root directory"... then it should be able to read them ok....