iPhone App: PageScanner

[univurshul]

Another question for your scan machine: Is it still suffering from camera orientation flip issue?

The preliminary hardware designs for the smartphone book scanner were experiencing this issue, although I know it is one in a few possible different scenarios. I am considering new hardware possibilities, and it has delayed my progress. I will update you with all possible flip/orientation issues while deploying 1 iPhone as the only capture device for book scanning, where the shuffle/merge feature will obviously play a role.

[univurshul]

Could you send me the camera apps list you tried? I would like to see how good they are.

Camera apps with white balance features:

Real Cam LE: There are good ideas here, but poorly executed in practice--with book scanning, that is. This app's approach to white balance is choosing 1 of 5 points on the display that should be white. But this wasn't effective on book pages and documents for me. So, if you could develop your own algorithm that allows the user to pinpoint white areas on the book page (even if the page appears orange from the lights, the pages are slightly off white, etc. where it calibrates the white balance as such) then that may help achieve a close color reproduction. What I also really like is the grid (book scanners will use this as a guide to minimize keystoned images on the page. And this leads me to another awesome feature for platen-hardware scanners: a level gizmo built into the preview/capture screen. This is really helpful if you are trying to calibrate the angle of the platen (book page) with the angle of the iPhone's camera lens; if they are both resting at the same angle, then you shouldn't have resulting keystone problems. A completely square image.

DualCam: Just released last week, I haven't bought this app to test yet until I see a few reviews, but it claims to have a white balance adjustment. The examples didn't show too much worth cheering about, but I suppose you never know until you try it.

ColorTemp: Another cool app I like, but haven't put to work yet. It operates on a system of measuring the temperature of light in relation to a pure white surface. It is not a camera app, nor does it take pictures, but I do like this approach and the science about it. This means if the you could calculate the temperature of your lights on the scanning system, then, PageScanner could adjust the white balance accordingly.

So far, the color balance apps look quite limited. I thought I saw more apps with white balance features. I thought a couple apps I already owned have white balance, but they basically have B/W and Sepia toy filters.

...But virtual filters area good idea too. Setting up a series of a few filters to choose from, say, LEDs, Halogens, CFLs, etc.

[litchie]

Real Cam LE: There are good ideas here, but poorly executed in practice--with book scanning, that is. This app's approach to white balance is choosing 1 of 5 points on the display that should be white. But this wasn't effective on book pages and documents for me. So, if you could develop your own algorithm that allows the user to pinpoint white areas on the book page (even if the page appears orange from the lights, the pages are slightly off white, etc. where it calibrates the white balance as such) then that may help achieve a close color reproduction. What I also really like is the grid (book scanners will use this as a guide to minimize keystoned images on the page. And this leads me to another awesome feature for platen-hardware scanners: a level gizmo built into the preview/capture screen. This is really helpful if you are trying to calibrate the angle of the platen (book page) with the angle of the iPhone's camera lens; if they are both resting at the same angle, then you shouldn't have resulting keystone problems. A completely square image.

So far, the color balance apps look quite limited. I thought I saw more apps with white balance features. I thought a couple apps I already owned have white balance, but they basically have B/W and Sepia toy filters.

...But virtual filters area good idea too. Setting up a series of a few filters to choose from, say, LEDs, Halogens, CFLs, etc.

I am quite enjoying your reviews, surely you keep an eye on what's happening in the appstore:)

There will be grids in the preview screen in next update, to help you align texts. About color balance, I am going to do some work to improve page scanner in scanning colorful pages. This feature will be there when it is done.

[litchie]

Page scanner updated to 2.1

TaylorR137 suggests that the previous version doesn't handle photos well. That is true because I focus on provide clear text at that time. Scanning with handheld iphone camera is very different from scanning with stable and well lit devices people built here, we need to deal with more complicated situation. And we often lost text details using ordinary binarization. Our goal is to make sure texts in low contrast condition should be as good as possible. After then I have been looking for a solution to process photos better and yet preserving clear texts. The latest version is my recent approach. Not optimal, but better than the previous one.

The optimal solution is to recognize the photo area and apply different processing for photo and text. But the recognize rate has to be close to 100% because we are going to use it in a batch way and don't have the chance to recover from damage. This is what I am going to work on next.

Other features included in this update:

- customizable global image contrast settings. Tune it according to your camera quality and lighting condition.
- Wifi file sharing, easier to share files without iTunes
- Camera overlay grid view to help alignment (continuous mode only)
- Unlock lite version

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[univurshul]

Very good work here, Litchie.

I was sidetracked on the smartphone build to finish a full size scanning system: (http://www.diybookscanner.org/forum/vie ... ?f=1&t=601).

I should have the first smartphone scanner design ready by late November. The largest it will scan will be comic books. Testing has determined books larger than this size are not quality reproductions for the iPhone 4.

The smartphone book scanner will utilize 1 iPhone, with an oscillating movement per page. It will be very portable with solar power capabilities.

I suppose if you are testing colors and pictures with PageScanner, comic books are the most comprehensive test for you, as Scan Tailor or any iPhone on-board processing will be handed quite the challenge with this type of material.

Best,

Univurshul

[litchie]

I saw your futuristic scanner earlier, well done!

At present page scanner's focus is on black&white. I do want to provide colorful scan ultimately.

Please send me your sample pages when you're working on your smartphone build, so I can make sure page scanner works best with your build.

Very good work here, Litchie.

I was sidetracked on the smartphone build to finish a full size scanning system: (http://www.diybookscanner.org/forum/vie ... ?f=1&t=601).

I should have the first smartphone scanner design ready by late November. The largest it will scan will be comic books. Testing has determined books larger than this size are not quality reproductions for the iPhone 4.

The smartphone book scanner will utilize 1 iPhone, with an oscillating movement per page. It will be very portable with solar power capabilities.

I suppose if you are testing colors and pictures with PageScanner, comic books are the most comprehensive test for you, as Scan Tailor or any iPhone on-board processing will be handed quite the challenge with this type of material.

Best,

Univurshul

[litchie]

Page Scanner 2.2 update is available.
- Fix memory issue on iphone4
- Fix auto take timer not customizable
- UI improvements