Algorithm improvement for Coca-Cola can shape recognition

One of the most interesting projects I've worked in the past couple years as I was still a student, was a final project about image processing. The goal was to develop a system to be able to recognize Coca-Cola cans (note that I'm stressing the word cans, you'll see why in a minute). You can see a sample below, with the can recognized in the green rectangle with scale and rotation.

GD vs ImageMagick vs Gmagick for jpg?

I am in the step to abandon GD for manipulating image in my website, they just sux .

OpenCV with Android

I'm just after setting up OpenCV for android in Eclipse following this tutorial , I have the samples which do not use native c running fine on my phone.

Render images by java code or read images from a static path?

Here's my code:

1.Java Code:

public static void getImg(Long itemId) {

  try {

    Item item = Item.findById(itemId);

    if (item.img != null && item.img.getFile() != null{

      response.setContentTypeIfNotSet(item.img.type());

      renderBinary(item.img.get());

    }

  } catch (Exception e) {

    Logger.error("Can't find image,itemId = " + itemId);

  }

} 



html : < img src="@{{ Items.getImage(123)}}"/>

Image features extraction

I have a visual marker like this one and a blob detection algorithm in Java .. How can I extract the regions of the image so that I can run the blob detection algorithm on each one separately so that it can detect 1, 1, 3 blobs respectively.

Handwritten character (English letters, kanji,etc.) analysis and correction

I would like to know how practical it would be to create a program which takes handwritten characters in some form, analyzes them, and offers corrections to the user. The inspiration for this idea is to have elementary school students in other countries or University students in America learn how to write in languages such as Japanese or Chinese where there are a lot of characters and even the slightest mistake can make a big difference.

UIImage Resize without loss of quality

Im looking for an external library (or a method using Apple frameworks that doesn't destroy the quality) which will let me scale down images.