Printing JPG files with GIMP 2.8

Question

I used to print my (with GIMP 2.6.11) modified images on my Canon Selphy CP780 printer without any problems. But now I use GIMP 2.8.2 and the modified and exported JPG files won't print anymore. Instead I see a big Question sign (?) in the Selphy display and not the image as expected. No chance to get a printout!

Has anybody experienced the same problem with the new GIMP application? Is there anything I must take care of (setting or removing options) when exporting modified images into the JPG format?

Answer 1

I don't know if this applies to the CP780, but I had the same problem with the CP900 and I managed to solve it. When exporting jpg in Gimp, be sure to use the following options:

• uncheck optimize
• uncheck progressive
• check Save thumbnail

I think the printer is using the exif thumbnail to display the image on the LCD rather than reading the whole image, so without the thumbnail this doesn't work, although I can't verify this.

You can also use ImageMagick convert and exiftool to remove interlacing if exists, create the thumbnail and load it into the exif data.

Assuming we're working with a file called work.jpg:

convert -interlace none work.jpg work.jpg

convert work.jpg -thumbnail '196x196>' work-thumb.jpg

exiftool "-ThumbnailImage<=work-thumb.jpg" work.jpg

This seems to create images that the CP900 can display on the LCD and print.

Answer 2

This problem has been bugging me for a long time. I believe I've finally found a solution.

The problem seems to be related to EXIF data, as is pointed out here (Post #18).

First scenario: I color corrected an image and it wouldn't print. I copied the EXIF data from the original photo using the following command and it printed correctly.

exiftool -tagsFromFile original.jpg color-corrected.jpg

Second scenario: I created an original drawing that I wanted to print. Deleting all EXIF data allowed me to print the photo.

exiftool -all= my-image.jpg

The only EXIF data that remains after that is the very basic amount, as can be seen using the command:

exiftool my-image.jpg

About my system: Editing with the GIMP on Linux, SELPHY CP740, printing from an SD card.

Answer 3

There are multiple pitfalls with the Selphy printers (I have a very hateful relationship with our CP910). Mostly it comes down to:

• The SD Card needs to be formated "correctly". If you cannot see a single one of your pictures on the card, this is probably your problem. Try to fix it by formating the SD Card directly, i.e. do not create a partition on the card but format the whole volume.

  sudo mkfs.vfat /dev/mmcblk0    # This works
  sudo mkfs.vfat /dev/mmcblk0p1  # Does not work
  

• The other usual problem is, that your jpg files are "broken". Only JPG is allowed. When exporting in Gimp uncheck all options (especially progressive). Only leave thumbnail on, this will give you a preview of your pictures on the printer.

I know the question is old, but I come back here every time I print a picture, and next time...

Answer 4

I managed to solve the problem on my Selphy CP910. The following two commands seem to fix any JPEG to print on the device using an SD card.

jpegtran -trim -copy none -outfile output.jpg original.jpg
exiftran -g -i output.jpg

The first command strips all extra information out of the JPEG, which allows the image to print, even though the preview just shows a question mark. (I'm not sure whether the -trim option is strictly required.)

The second command regenerates the EXIF thumbnail so that you also see the preview image on the device.