What is a digital image

With the continuous development and application of digital technology, many information in real life can be processed and stored in digital form. Digital images are such images stored and processed in digital form. Using a computer, it can perform processing that can not be realized by the usual image processing technology. It can also be transmitted on the Internet and can be copied without distortion.

First, the method of obtaining images

Many images with images use analog images such as 35mm slides, transmissive films, or reflective films. To obtain a digital image, the pixels in the image must be converted into digital information for processing and processing on the computer. The job of converting analog images into digital images is usually done by a scanner. The scanner measures the light emitted or reflected from the picture, sequentially records the value of the spot and produces a digital copy of the color or black and white. This image is translated into a series of numbers and stored on the computer's hard disk or other electronic medium such as a removable hard disk, a graphic CD or a recording tape. Once the image is converted into a digital file, it can be electronically transferred from one computer to another.

Terms to understand

Simulation image - a data stored in a continuous form. For example, a photo taken with a traditional camera at the beach is a simulated image.

Digital image - data processed with binary digits (such as on and off), such as digital photographs taken with a digital camera.

Scanner - A digitized input device that produces a copy of a bitmap for electronic processing.

Second, the digital method of design planning

A wide range of applications can support digital image processing, such as generating digital graphics, modifying digital images, performing some technical processing such as page design, and combining some pixels in one image.

The images produced by applying these software are divided into two major categories, vector graphics and bitmap images.

Vector graphics are often used for segment plots, logo statements, and any image that requires a smooth transition to sharp edges. One of the advantages of vector graphics is that they can be arbitrarily zoomed in and out without losing detail or clarity and without being distorted.

Bitmap images are usually images such as pictures or photos, such as those obtained with a scanner. The bitmap image uses the software in the scanner to “map” the image information into a corresponding space in the virtual graphics grid, and the color pixels fill each of the cells to form the entire image. Unlike vector graphics, bitmap images cannot be arbitrarily enlarged without very good image quality. When the image is enlarged, the pixel grid size also increases accordingly, and the sharpness decreases. Therefore, in order to obtain sufficient image details, it is important to select the size of the scanned bitmap image. Bitmap image files are usually much larger than vector graphics files because more information is needed to recreate images.

There are many formats used to describe graphic image files. Two of the most widely used are the TIFF (Tagged Image File Format) format and the EPS (Ecapsulated Postscript) format. TIFF is a commonly used bitmap image format, and vector graphics are similar to EPS files. Different types of graphic image files can be combined and designed and formatted in a common file format.

After the design layout is completed, all the pixels are concentrated in a file, which can contain vector graphics and bitmap images stored in different file formats. This file can be converted to a raster graphics format file (a bitmap format) required by the output device. The size of the raster in the output device is fixed, depending on the resolution of the output device. At this point, all pixels in the file, regardless of the original format, will be bitmapped so that the output device can reproduce the image.

Need to understand the terms

Vector graphics - A graphic file that can be arbitrarily scaled without loss of detail.

Bitmap Image - An image file stored in pixel or dot format.

Raster Image Processor - A hardware-software device that converts a graphic file into a series of points for output.

Resolution - also known as resolution, the number of pixels per unit length, the common unit is dpi (pixels/inch).

Third, digital image reproduction method

Different technologies can be used to produce digital images on a wide-format output device. Liquid ink jet technology, electrostatic technology, solid ink jet technology, thermal conversion technology, and photographic technology are some of the major technologies used today.

Here are some general introductions to several technologies:

Inkjet technology

As needed, the ink is forced to drop onto the medium that needs to produce the image by applying pressure.

Continuity - The ink continuously forms a jet of ink droplets under pressure and is ejected onto the medium where the image needs to be formed.

Thermal Effect - Bubbles form at the nozzle opening. The bubble pressure pushes the ink droplets onto the media.

Solid ink - The ink is stored in solid form, melted when needed, and printed on the media in a manner similar to liquid ink jetting.

Heat-sensitive wax or thermal resin conversion technology

Waxes or resins are used in film carriers, usually in the form of rollers. The wax or resin is transferred onto the media by heating, and each color must be separately transferred.

Dye Sublimation Technology

Similar to the thermal conversion technique, when the controlled heat source heats up, the dye-sublimation dye is evaporated from the carrier roll onto the medium.

Electrostatic technology

The electrostatically charged image on special media, electrostatically attracts colored particles to form a color image, and the images printed by typical electrostatic printers are separated by each color.

Atomized sputtering

Separately placed color ink is sprayed directly onto the media through the nozzle.

Digital images can be applied to paper media, vinyl film media, fabrics, plastics, and many other materials. The most suitable output devices and media can be selected as needed.

Fourth, post-processing

The use of special media, ink, or roll-imaged images are all able to withstand the effects of the sun and changes in daily weather conditions. Similarly, stickers also provide opportunities for digital images to be used to prepare surfaces for objects. You can see digital images on any decorative surface of a bus, airplane, building, ceramics, knitwear, etc.

Digital image technology is changing the way we handle images. It has many advantages:

When it comes to visual information exchange, digital images change the habits. A few years ago, the cost, color, format, and print cycle were four major challenges faced by large format image demanders. Now that digital technology has successfully entered the role, the production of large-format images is more convenient and practical than ever before.

Here's how digital image technology breaks through these four major challenges:

Cost - The cost of digital proofing or preprinting is significantly lower than traditional proofs, making the price of short live and single proofs for producing full-color images within an acceptable range.

Color - For many projects, traditional proofing is simply too expensive, and digital images are a color processing process that eliminates expensive proofing steps.

Size - Digital image technology can actually handle any size of image, the existing output device can be from a few inches to more than 60 feet wide, for larger images can be completed using a piece-by-piece method.

Print cycle - Digital image processing is an automated process that can quickly operate and change images. Digital image technology can be used to instantly modify image content and textual information.