Question

My current project is about android image processing.But if my phone camera is about 1-2 megapixel, will it affect the result of preprocessing like grayscale and binarization?

Answer 1

Your phone camera won’t affect any pre-processing you perform in that your pre-processing code will act just the same regardless of the number of megapixels in your camera. Garbage in, garbage out still does apply. If you start with a low quality, poor contrast, blurred picture, you aren’t going to be able to turn it in to something fantastic you want to hang on your wall. Additionally, as Mizuki alluded to in his comment, a 1-2 megapixel phone image is far higher resolution than the average image used on the internet, and these can be binarised and greyscaled just fine.

As for the two methods of preprocessing you mentioned in your question:

Binarization

This just converts an image into a two colour version. Normally black and white, though other colours are possible. The number of pixels in the image doesn’t matter for this, other than it taking longer if it has more pixels to process. Low quality mobile phone cameras can sometimes produce low contrast photos and this may make it harder for the binarization algorithm to correctly determine the threshold at which pixels should be displayed in either colour.

Greyscale

Converting an image to greyscale is done by manipulating the colours of each pixel so, again, the number of pixels should only increase the preprocessing time, not change the result.