ICO is a format (full name - Icon File) of bitmap images and refers to system files. Developed by Microsoft and designed to store icons in its operating system. ICO files, as a rule, store icon images - modest in size, with a small resolution (from 16x16 to 64x64 pixels), with different color depths (from 16 colors). In the graphical interface of various operating systems, ICO format files are used to display files, programs and folders (primarily in Windows) or as an icon for a specific website.
J2C is an advanced version of the JPEG format, which is now widely adopted in order to transfer and store digital images. This is a raster image category file. Full name - JPEG 2000 Code Stream. The J2C file format was created by Joint Photographic Experts Group. A format is a lot of advanced features, including efficient coding. The .j2c file extension is a JPEG 2000 image file. This bitmap is created using JPEG 2000 compression. The compression is close to standard .JPG compression. However, it uses a new coding standard, and it is flexible due to computational complexity. Many applications that support standard .JP2 files can view it. A file with the J2C extension opens in the Windows operating system. To view and process a bitmap image in J2C format, you need to use programs such as Corel PaintShop Pro X9, IvanView, ACD Systems Canvas 16, ImageMagick. Using the programs that have been listed, you can convert images, pictures and drawings of the specified format.