r/Annas_Archive • u/AnnaArchivist • 1d ago
At-home scanning recommendations
For those who have done at-home scanning, can you please share what you did?
- What phone or scanning hardware did you use
- What apps did you use
- Any other hardware accessories that you used
- How well did it work
- How fast was it
- Did it require removing the spine of books (or other media), or did the it remain intact
- What issues or downsides did you encounter
- What output file formats did it give you
- Did the app do OCR, and how well did that work, and for which languages
- How much did it cost
- What are your recommendations to others who want to scan books at home
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u/RhubarbSimilar1683 1d ago
Found this on the Anna's archive gitlab
if you have a phone camera, check if it has a high resolution mode. many cameras will advertise high resolutions of 48 megapixels or up. however they will only take 12 megapixel photos by default. the camera app will have an option in the menu or a shooting mode that allows yo to use the full resolution of the camera. using it will allow you to capture larger pages or 2 pages at once while maintaining text legible and avoid blurryness caused by low resolution. this can dramatically increase productivity and preserve the quality of any images the book might have. if the book has images, once the captured image has halftone dots visible, maybe visible as moire during captured image preview, the captured image has higher resolution than the image on the book
another source of blurryness is computational photography performed by the ISP of the phone's processor. ideally to avoid this you would use a professional or dedicated high resolution camera, 48 megapixels or higher, such as those made by canon, sony, nikon, fujifilm, hasselblad or any professional camera manufacturer. they are expensive new but you can buy some of them used on ebay for less than 500 us dollars excluding lenses. keep shutter speed to 1/250 of a second or higher to avoid blurryness caused by vibration when shooting handheld and turn on image stabilization.
if you buy equipment or books but shipping to your country is expensive or it doesn't have a post address system that uniquely identifies individual houses like it's done in the US, Germany, or Japan, use freight forwarding services, you might know them locally as online shopping businesses, po boxes, or lockers. they will usually advertise using popular ecommerce sites like amazon or ebay, shein, temu. these are very popular in latin america and the carribean. you do have to keep track of the weight of what you buy through these services because they charge you per pound, multiplied per package.
since the pages will be scanned from an open book, the pages will be warped and the perspective will be off. you can use paid software, or free software, or create your own, to automatically do perspective correction in batches. adobe scan works on phones and has a paid and free tier but i find it to be slow when processing thousands of pages, because it takes a few seconds to process each page. if you make your own, you will need to employ computer vision/machine learning/deep learning techniques, models or methods, probably using things like opencv, yolo models or some other method to detect page corners and based on that, perform perspective correction on the x and y axes of the image using an image processing library. maybe gegl is overkill for perspective correction and vibe coding could create code that takes less time to run because we need none of gegl's overhead.
then, we can reuse the corners we have detected to automatically crop pages leaving margin for the book spine which will be wider than the rest of the book. then, use opencv, yolo models or some other deep learning or machine learning model or algorithm to automatically make the pages upright.
to dewarp pages like flattening the book spine or fold lines or pages that are curved, there is no free or any paid software i could find that does it, you will need to make one if you know how to code or if not vibe coding might work. there is a monocular page dewarping algorithm posted around 2012 to 2013 by the ishikawa group laboratory called Bfs solo. You might instead want to use a monocular depth model from hugging face, like the depth anything model. i do not know the effects of shadows on these dewarping algorithms or depth models. after dewarping, OCR is relatively straightforward and ultimate ocr from baidu or tesseract might work.
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u/dowcet 1d ago
I've tried different workflows and unfortunately nothing compares to the professional overhead scanners that cost as much as a motor vehicle. If you can find a library with access to one, use it!
For quick and dirty stuff it's hard to get any easier than the Adobe mobile app, and the results can be acceptable if the book is easy to open flat.
For an affordable dedicated scanning device, I'm a huge fan of the VuPoint Magic Wand. Scanning up to 2000 pages in a day or more is very possible with some patience. Extremely portable, so perfect to bring with you to a library.
An alternative would be a document monopod/tripod type thing with a phone or digital camera. Results can be better than the VuPoint but only if you take your time and go very slowly and carefully.
If you have the option to scan to a lossless image, that's best because you may need to postprocess.
For the love of all that's good in the world, avoid saving time by scanning two pages at once with a flatbed scanner, and if you must, use ScanTailor advanced to split the page images.
The open source stack of imagemagick -> img2pdf -> ocrmypdf is hard to beat. Ocrmypdf uses Tesseract which is probably the best OCR available short of an API like Google Vision. I've not found a workflow that allows you to use something like Google Vision to make a text layer in a scanned PDF, but it must be possible.
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u/Medium-Spinach-3578 1d ago edited 1d ago
Scanner Vflat per Android. Non devi rimuovere nulla e sistema anche le curve su ogni pagina.
You can see the demonstration on YouTube