What is a CT file?
A CT (Continuous Tone) file is a raster image file used by Scitex graphics processing equipment. Several graphics suites such as Adobe Photoshop, Adobe InDesign, and QuarkXPress supports its usage for rendering. Data image is stored inside the CT file in CMYK (Cyan, Magenta, Yellow Key), RGB, and grayscale image formats, but they don’t support alpha channels. CT files can be opened with applications such as Adobe Photoshop 2022, Adobe InDesign 2022, and XnViewMP.
CT File Format
A Scitex CT file consists of a control block, a parameter block, and the image data as per this CT Wikipedia article. The file format specifications of CT file format are not available but some research has shown that a CT image represents 4 colors, with each colored pixel being up to 128 bits in size. CT files are usually large in size and enables high-quality images.