The File Extensions Database

.CTG File Extension

  • Developer by: Canon
  • Category: Misc Files

What is an .CTG file?

.CTG is Canon Digital Camera Catalog File

A CTG file is a catalog index file created by Canon digital cameras. It contains information about the number of images stored in each folder on a camera's memory card (typically up to 99). CTG files are stored in the CANONMSC folder and they correspond to other folders saved on the memory card.

You should not manually open or edit CTG files. The camera will automatically delete the CTG files when the corresponding images are erased.

NOTE: CTG files are much smaller than .JPG files and do not contain any image data. Therefore they cannot be converted to JPEG files.

Common CTG Filenames

382.ctg - This is an example of a CTG filename. It contains information about images in the "382CANON" folder.

How to solve problems with CTG files

  • Associate the CTG file extension with the correct application. On :
    Windows: Right click on any CTG file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.CTG files". Mac: Right click (or Ctrl-click) the CTG file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .CTG is Canon Digital Camera Catalog File. Because only the current version supports the latest CTG file format. Search, therefore, e.g. on the Canon manufacturer website after an available .CTG is Canon Digital Camera Catalog File update.
  • To make sure that your CTG file is not corrupted or virus-infected, get the file again and scan it with antivirus software.