Fundamentals of Image Formation
Image formation is an analog to digital conversion of an image with the help of 2D Sampling and Quantization techniques that is done by the capturing devices like cameras. In general, we see a 2D view of the 3D world.
In the same way, the formation of the analog image took place. It is basically a conversion of the 3D world that is our analog image to a 2D world that is our Digital image.
Generally, a frame grabber or a digitizer is used for sampling and quantizing the analog signals.
The mapping of a 3D world object into a 2D digital image plane is called imaging. In order to do so, each point on the 3D object must correspond to the image plane. We all know that light reflects from every object that we see thus enabling us to capture all those light-reflecting points in our image plane.
Various factors determine the quality of the image like spatial factors or the lens of the capturing device.
Color and Pixelation:
In digital imaging, a frame grabber is placed at the image plane which is like a sensor. It aims to focus the light on it and the continuous image is pixelated via the reflected light by the 3D object. The light that is focused on the sensor generates an electronic signal.
Each pixel that is formed may be colored or grey depending on the intensity of the sampling and quantization of the light that is reflected and the electronic signal that is generated via them.
All these pixels form a digital image. The density of these pixels determines the image quality. The more the density the more the clear and high-resolution image we will get.
Forming a Digital Image:
In order to form or create an image that is digital in nature, we need to have a continuous conversion of data into a digital form. Thus, we require two main steps to do so:
- Sampling (2D): Sampling is a spatial resolution of the digital image. And the rate of sampling determines the quality of the digitized image. The magnitude of the sampled image is determined as a value in image processing. It is related to the coordinates values of the image.
- Quantization: Quantization is the number of grey levels in the digital image. The transition of the continuous values from the image function to its digital equivalent is called quantization. It is related to the intensity values of the image.
- The normal human being acquires a high level of quantization levels to get the fine shading details of the image. The more quantization levels will result in the more clear image.