One of the most useful features of Evernote and OneNote is Image OCR. When you clip an image - be it a screenshot, a scanned business card, or a picture of the whiteboard - these tools automatically detect the text inside the image and make the image searchable.
Gmail text search has always been very capable but some might not know that Gmail, like Evernote, also performs OCR on images contained in email messages. When you perform searches inside Gmail or Google Inbox, the results always contain matching images that contain the search keywords.
I tried Gmail OCR search against different types of images and the results were fairly good. Text recognition in Gmail works for both image attachments as well as inline embedded images.
Gmail could successfully find matching text inside product manuals with small fonts, scanned book cover and a handwritten note but failed with logos and some street signs.
Scanned Picture (Pass)
Handwritten Note (Pass)
Product manual with small fonts (Pass)
Street Sign (Fail)
Google Drive and Google Keep are other Google products that offer you the ability to search for text within stored images. In the case of Google Keep, you also have the option to extract the text detected inside in an image and store it within the note itself.
Also see: Reverse Image Search on Mobile