You can select DataManager source: File Metadata block and select the images folder. Choose Images file type, and tick "in file content" tags. Omniscope will be able to populate the table with basic data including the File name/Extension/Category/Size (MB)/ Full path/Pixel width/height and more, depending on the metadata content.
If you scanned a card with number 5 on it, then saved it as a jpg image, Visokio would not be able to 'read' the character and place it in a table field. You need specialist OCR (optical character recognition) software to extract words from images, then connect the output to Omniscope.
Nitiwan - Optical character recognition (OCR) programs are designed to solve the problem of converting images to more structured but still 'raw' data sets that can be futher processed.
Seach the web for "OCR PDF JPG" and you will see many options to pre-process your scanned images in PDF format and convert into a data file format that can be text mined or otherwise enriched. There are some free trial services available to start with.