The concept of image

The concept of image: a drawn, photographed or printed image.

Images are the basis of human vision, an objective reflection of natural scenery, and an important source for humans to understand the world and humans themselves. "Picture" is the distribution of light reflected or transmitted by an object. "Image" is the impression or understanding of the picture in the human brain that is accepted by the human visual system. Photos, paintings, cliparts, maps, calligraphy works, handwriting sinology , faxes, satellite cloud images, film and television images, X-rays, electroencephalograms, electrocardiograms, etc. are all images.

Basic meaning

Image is a similar and vivid description or portrait of an objective object. It is the most commonly used information carrier in human social activities. In other words, an image is a representation of an objective object, which contains information about the described object. It is people's primary source of information. According to statistics, about 75% of the information a person obtains comes from vision.

In a broad sense, images are all pictures with visual effects, including: on paper media, on negatives or photos, on television, projectors or computer screens. Images can be divided into two categories according to the way they are recorded: analog images and digital images. Analog images can record image brightness information through changes in the intensity of a certain physical quantity (such as light, electricity, etc.), such as analog TV images; while digital images use computer-stored data to record the brightness information of each point on the image.

Junyouhui, an international image art promotion organization, explains the image processing process as follows: Image processing is a technology that analyzes, processes and processes images to meet visual, psychological and other requirements. Image processing is an application of signal processing in the image domain. Most images are stored in digital form, so image processing often refers to digital image processing.

In addition, analog image processing methods based on optical theory still occupy an important position. Image processing is a subcategory of signal processing, and is also closely related to fields such as computer science and artificial intelligence. Many traditional one-dimensional signal processing methods and concepts can still be directly applied to image processing, such as noise reduction, quantization, etc. However, the image is a two-dimensional signal. Compared with the one-dimensional signal, it has its own special side, and the processing methods and angles are also different.

A few decades ago, image processing was mostly performed by optical devices in analog mode. Due to the inherent parallel nature of these optical methods, they still occupy a central position in many application fields, such as holography. However, due to the substantial increase in computer speed, these technologies are rapidly being replaced by digital image processing methods.

In general terms, digital image processing technology is more universal, reliable and accurate. They are also easier to implement than simulation methods. Specialized hardware is used for digital image processing, for example, pipeline-based computer architectures have achieved great commercial success in this regard. Today, hardware solutions are widely used in video processing systems, but commercial image processing tasks are still basically implemented in the form of software, running on general-purpose personal computers.