Canon jpeg format

[Bill_Bruen]

I've downloaded pix from my S50, reworked them in PS7, resaved them as jpegs and reloaded them to my flashcard hoping to print them with my CP100.

However the camera says the jpeg files are an incompatible format and just display a small image.

So, Canon jpegs are different in some way.

Anyone know how?

Even better, anyone know how I can resave them in Canon jpeg format so that the camera will accept them?

[Guillermo Freige]

The problem usually isn't the JPEG format, but the EXIF data stored in it. Canon uses the EXIF data extensively, and you modified that when you resaved it in PS7. You can use some EXIF-data saving program before editing (I don't remember the name now, but someone mentioned it in the forum. Make a search), and then use it to restore that info, and check if it works. Also save the image in quality 9 or less, to use 4:2:2 color subsamping, as used by Canon JPEGs

[Bill_Bruen]

Thanks Guillermo....Exifer seems to be the program.

I'll give it a try, but of course I've already lost the data for the pix I've edited.

[Guillermo Freige]

To test, paste the info from another picture, if all you want is to be able to see the picture in-camera.

[Bill_Bruen]

Well, I've now tried the Exifer program, saved the Exif data and reapplied it to a Quality 8 jpeg saved in Photoshop 7.

When I view the pic in the camera I get a very small thumbnail...not fullscreen....this is an improvement on the question mark I had been getting......but I'm still getting the message 'Incompatible jpeg format'.

Incidentally, PS7 does save some Exif data when you save to jpeg, but doesn't have as much data as Exifer finds.

I can't believe Canon don't have a workround to fix this problem so I've emailed Canon Support and will report back here their response.

Meanwhile, if anyone else has successfully done what I'm trying to do....please do tell how........

[marcel wouters]

I don't think you could succeed without patching the jpeg file!
I got the same problem with the PIM plugin!
Both the direct print interface and the PIM plugin are designed to run on an untouched image (not edited), why?? because they use exif data to correct exposure-contrast-colors etc. Once the image is edited all those data becomes irrelevant and the automated correction could not be applied.
Try this..take a raw image then convert with FVU in jpeg (that's a Canon utility), all exif data should be there!
Try to print from your card! This doesn't work with PIM, there is a difference somewhere!

[jfike]

I treat all my G2 images as "negatives" just like my 35mm film cameras. I transfer, rename, and then store the files in a zip archive, saving to a CD. Then I edit copies of those files for display, etc.

I wrote a small C program to do a batch file rename in a directory. First, I enter a text tag (like "travel") then the initial file to rename (say, IMG_1422.jpg) and then a new increment number. If I enter an increment number of 2013, each file will be sequentially renamed travel2013.jpg, travel2014.jpg, etc, until it hits a non-existent file. I keep a MS Access database, keyed to those filenames.

[Bill_Bruen]

Well, Canon have finally replied with a fairly curt comment. They say what I am trying to do cannot be done.

Their recommendation is to buy their connection kit to attach the CP100 to the PC and use Zoombrowser.

I've now done this and it works OK, but I'm going to start a new thread about matching screen and printer output, as my prints are not as good as the edited images I see on my screen.

[pallosp]

I had the same "Incompatible JPEG" error message when I tried to upload screenshots to my Canon PowerShot A720 camera's SD card. I've read a lot of forums about the issue, and I didn't find any good solutions there, so I started investigating what the camera expects about the JPEGs.

I opened an image taken by A720 and tried some different settings for saving in Paint Shop Pro. The results:

- The image was still readable after deleting its EXIF data.
- The encoding must be kept standard, progressive and lossless JPEGs aren't supported.
- The compression factor doesn't matter.
- Some chroma subsampling modes work (e.g. YCbCr 1x1 1x1 1x1 or YCbCr 2x2 2x2 1x1), some don't (e.g. YCbCr 4x4 2x2 2x2).
- Embedded ICC profile can be either checked or unchecked.
- The width and the height must be the multiple of 8 (that's why I didn't manage to view the uploaded screenshots from my 1400x1050 screen).
- The file naming convention must be obeyed. The A720 camera only accepts files called IMG_xxxx.jpg, where xxxx is a 4-digit number.

The A720 fails to read JPEGs created by Irfanview with "Unidentified Image" message, however it still shows the thumbnails if the EXIF info was kept. I didn't find what combination of settings may forced Irfanview to save the image in Canon-compatible format. Anyway Paint Shop Pro can fix the images saved by Irfanview.

[pallosp]

Update: the free Paint.NET also saves to Canon A720-compatible jpegs. The only constraint is the image size: its width and the height must be the multiple of 8.
Unfortunately Paint.NET can't create EXIF thumbnails, so when zoomed out completely, the camera will only show question marks instead of the 9 small pictures.