Image processing is the process of analyzing and transforming an image on a computer. It aims to improve the storage of digital information, and make work with images more automated and efficient.
Image processing is used in a variety of fields, including medical imaging and biomedical engineering. It is also applied to the design of materials and industrial components.
Image Reconstruction
Image reconstruction is the process of transforming raw data from an imaging system into images that can be interpreted clinically. This process is used in magnetic resonance imaging (MRI) and can be applied to many other modalities such as radiography, CT scanning, and ultrasound.
There are several steps in the image reconstruction process and each one impacts the quality of the reconstructed image. Some are common to most reconstruction algorithms and others serve specialized functions for specific applications.
The main goal of the reconstruction process is to transform the raw k-space signal into an image that can be interpreted clinically. This can be accomplished by analyzing the raw data, calculating a description of gradient manipulations that occurred during the measurement, and applying signal processing to the data.
Typical image reconstruction components include noise pre-whitening, interpolation to reconstruct square pixels, filtering to reduce Gibbs ringing artifacts, Fourier transforms, and phased array coil combination.
The iterative reconstruction method involves a feedback process that permits sequential adjustments of an estimated image so that its virtual acquisition corresponds to the raw acquisition. This algorithm can be applied to any tomographic problem that can be expressed in a linear relationship between the image pixels and projection bins.
Image Enhancement
Image enhancement is a method of changing a digital image so that it is suitable for displaying or further analysis. It can be used to remove noise, sharpen or brighten an image, and make it easier to identify key features.
There are many different types of Image Enhancement methods. The most popular technique is Histogram Equalization (HE), which flattens and stretches the dynamic range of an image’s histogram. It also automatically reduces contrast in very light or dark parts of an image that are associated with the tail of a normally distributed histogram.
Another popular technique is Nonlinear Contrast Enhancement, which uses adaptive gamma correction to improve the quality of a digital image. It uses information about the original input and output images to adjust the parameters of a contrast enhancement algorithm.
Another type of Image Enhancement technique is Global Contrast Enhancement, which considers the entire image for enhancement. This technique ignores local information and is computationally complex, but it can be used to enhance images in all regions of the image at once.
Image Compression
Image compression is a technique used to reduce the size of digital images without degrading their quality. It can also be used to reduce storage costs and the time it takes for images to be sent over the Internet or downloaded from a web page.
Typically, there are two kinds of image compression methods: lossless and lossy. Lossless image compression is ideal for most applications because it preserves all of the original data in the image file.
When a lossy method is used, the image file is reduced by permanently removing less critical information. This can result in a significant decrease in file size, but it can also cause distortions or other problems.
There are several different types of lossy compression methods, including vector quantization, predictive coding, transform coding and hybrid coding. Each of these has its own unique benefits and drawbacks.
Transform encoding is a common lossy compression method that groups colors that have similar shades together into one value. It can be particularly effective for JPEGs and other formats with a lot of shades.
Another common method is chroma subsampling. This is a color space reduction technique that takes advantage of the fact that the human eye perceives brightness more sharply than colors, reducing the amount of chrominance information in an image.
Image compression is useful for many purposes, and there are a wide range of techniques available to suit different needs. However, it is important to understand that different compression techniques will have different advantages and disadvantages for different types of images.
Image Restoration
Image Restoration is a branch of image processing that is used to retrieve an uncorrupted, original image from blurred or noisy images due to various reasons. These include camera motion blur, environmental effects, and noise caused by electronic components.
Several methods are commonly used in image restoration, including inverse filtering and Wiener filtering. However, these methods do not completely recover the original image from the damaged state.
Therefore, more advanced techniques are required to restore the image in a correct manner. Among the simplest methods are those based on a spatial convolution filter (i.e., motion blur kernel).
These methods can restore the image by filtering out the degradation. They are also very effective in removing noise.
Another important technique is image restoration based on sample blocks. This is a technique that can be applied to the restoration of a wide range of images. It can be used for the removal of objects in portraits and subtitles, as well as for repairing damaged photo paintings.
This paper introduces a new image restoration algorithm based on sample blocks. This algorithm focuses on the restoration of damaged areas that contain rich texture information. Traditional sparse representation image restoration algorithms use a fixed dictionary atom size to repair a texture area, which makes the restoration process more difficult. This paper proposes an improved algorithm, which is better at repairing both damage and blur.
Image Segmentation
Image segmentation is a key component of many computer vision applications and algorithms. It is used in medical imaging, computer vision for autonomous vehicles, face recognition and detection, video surveillance, and satellite image analysis.
The goal of image segmentation is to group similar parts of an image under their class labels. Depending on the context of the application, this can be done either as an image classification task (semantic segmentation) or as partitioning of individual objects (instance segmentation).
Semantic segmentation performs pixel-level class labeling with a set of object categories such as people, sky, cars, and trees. This task is usually more informative than instance segmentation, which separates distinct objects from the same class and provides a polygon bounding box or object segmentation map for each instance of a given class.
Instance segmentation enables us to distinguish between two different objects of the same class by giving each one a distinct color. It is a more complex and challenging task than semantic segmentation, but it is often useful when there is a lot of information to be conveyed in an image, such as detecting the boundaries between different people in a photo or separating a car from its background.
Various image segmentation algorithms have been developed over the years. Some of them include thresholding, histogram-based bundling, region growing, k-means clustering, and watersheds. More advanced methods are based on active contours, graph cuts, conditional and Markov random fields, and sparsity-based techniques.
Image Recognition
Image Recognition is a technique used to recognize objects in an image. It uses different computer vision techniques and machine learning algorithms to get the necessary results.
This technology is used for a wide range of tasks like object detection, classification, and image segmentation. It can also be applied in visual search, a technique that enables users to find information by matching an image with its features.
Despite the popularity of this technology, there are still many challenges that need to be solved for its widespread use. These include inter-class variation, occlusion, and noise.
However, with the advent of GPUs (Graphic Processing Units), new advancements in neural networks have been made. This has given rise to image recognition systems that are capable of recognising objects at a much higher level of accuracy.
These AI-based systems can help to automate various business processes, which can help to improve efficiency and productivity. For example, machines can be trained to detect blemishes in paintwork or foodstuffs that do not meet the expected quality standards.
Another popular application of this technology is security. A drone equipped with high-resolution cameras can be programmed to patrol a particular area and detect suspicious people or vehicles.
The use of Image Processing technologies is widespread across a variety of industries and sectors, with applications ranging from intelligent video surveillance to smart home automation. This technology has even become a critical component of military and national border security.