Urgent! Traditional pre-press processing technology to help me explain

With the continuous development and application of digital technology, many of the real-life information can be processed and stored in digital form of data, digital image is this digital form of storage and processing of images. The use of computers can be often present image processing technology can not be realized processing, but also can be transmitted on the Internet, can be copied many times without distortion.

First, the method of obtaining images

Many documents with images use analog images such as 35mm slides, transparencies or reflectors. To obtain a digital image you must convert the pixels in the image into digital information for processing and manipulation on a computer. The conversion of an analog image into a digital image can usually be done by a scanner. The scanner measures the light emitted or reflected from the picture, records the values of the light points in sequence and produces a digital copy in 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 media such as removable hard disks, graphic CDs or recording tapes. Once the image is converted to a digital file, it can be electronically transferred from one computer to another.

Terms to know

Analog image - a piece of data stored in a continuous form. For example, a photograph taken at the beach with a conventional camera is an analog image.

Digital image - data processed in binary digits (e.g., passes and breaks), such as a digital photograph taken with a digital camera.

Scanner - a digital input device that produces a copy of a bitmap to be processed electronically.

Second, the method of digitizing the design plan

A wide range of software applications can support digital image processing, such as generating digital graphics, modifying digital pictures, carrying out some technical processes such as page design, and combining a number of pixels in a single image.

The images produced by the application of these software are categorized into two main groups, vector graphics and bitmap images.

Vector graphics are often used for line drawing, marking statements, and any image that requires smooth transitions with crisp edges. One of the advantages of vector graphics is that they can be scaled up and down arbitrarily without loss of detail, clarity, or distortion.

Bitmap images are usually images such as pictures or photographs, such as those obtained with a scanner. Bitmap images use software in the scanner to "map" the information in the picture to the corresponding space in a virtual graphics grid, with colored pixels filling each cell, thus making up the entire image. Unlike vector graphics, bitmap images cannot be enlarged arbitrarily without very good image quality. When the image is enlarged, the pixel grid size increases accordingly and sharpness decreases. Therefore it is important to choose the size of the scanned bitmap image in order to obtain sufficient image detail. Bitmap image files are typically much larger than vector graphics files because more information is needed to regenerate the image.

There are a number of formats used to describe graphic image files, and two of the most widely used are the TIFF (Tagged Image File Format) format and the EPS (Ecapsulated Postscript) format.TIFF is the commonly used bitmap image format, while vector graphics are similar to EPS files. The different types of graphic image files can be combined to design and layout in a common file format.

After the design is laid out, all of the pixels are organized in a single file that can contain both vector graphics and bitmap images stored in different file formats. This file can be converted to a raster graphics format file (a form of bitmap) required by the output device. The size of the raster in the output device is fixed and depends on the resolution of the output device. At this point all the pixels in the file, regardless of the original format, are bitmapped so that the output device can reproduce the image.

Terms to know

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

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

Raster image processor - a hardware and software device that converts a graphics file into a series of points of data required for output.

Resolution - also known as resolution, the number of pixels per unit length, commonly measured in dpi (pixels per inch).

Third, the method of digital image reproduction

The use of different technologies can produce digital images on a wide-format output device, which liquid inkjet technology, electrostatic technology, solid inkjet technology, thermal conversion technology, and photographic technology are several major technologies used today.

Here is a general overview of the technologies:

Inkjet Technology

Ink is forced to drop onto the media to be used to produce the image by applying pressure as needed.

Continuous - the ink is continuously formed into a jet of droplets under pressure and sprayed onto the medium where the image needs to be formed.

Thermal effect - bubbles are created at the nozzle opening and the pressure of the bubbles pushes the ink droplets onto the media.

Solid ink - the ink is stored in a solid form, melted when needed, and printed on the medium in a similar way to a liquid ink jet.

Thermal Wax or Thermal Resin Conversion Technology

Waxes or resins are used in film carriers, usually in roller form. The wax or resin is transferred to the media by heat and each color must be transferred separately.

Dye Thermal Sublimation Technology

Similar to thermal transfer technology, thermal sublimation dyes are evaporated from the carrier roll and transferred to the media when heat is generated by a controlled heat source.

Electrostatic technology

Special media with electrostatic charges on the image, static electricity attracts colored particles to form a color image, typical electrostatic printers hit the image of each color is separate.

Atomized sputtering technology

Individually placed colored ink is sputtered directly onto the media through a nozzle.

Digital images can be applied to paper media, vinyl film media, fiber fabrics, plastics, and many other materials, and the most appropriate output device and media can be selected as needed.

Fourth, post-processing

The use of special media, ink or roll imaging images, are able to withstand the effects of sunlight and daily changes in weather conditions. Similarly, self-adhesive also gives the opportunity to apply digital images to the surface of the prepared kind of object. You can see digital images on public **** cars, airplanes, buildings, ceramics, knitted fabrics, and any other surface that can be decorated with patterns.

Digital imaging technology is changing the way we work with images, and it has many advantages:

When it comes to communicating visual information, digital imaging has changed habits. A few years ago, cost, color, format, and print cycle time were the four main challenges faced by those who demanded large format images. Now digital technology has successfully stepped into the role, making the production of large format images more accessible, practical and affordable than ever before.

The following describes how digital imaging technology breaks through these four major challenges:

Cost - the cost of digital proofing or pre-printing is significantly lower than traditional proofing, allowing the production of full-color images of short-run jobs and sheet-fed proofs to be priced within an acceptable range.

Color - For many projects, traditional proofing is simply too expensive, and digital imaging is a color process that eliminates the expensive proofing step.

Size - Digital imaging technology can handle virtually any size picture, and the width of existing output devices can range from a few inches to more than 60 feet, and for larger pictures this can be accomplished using a split-piece collage approach.

Printing cycle - digital image processing is an automated process that can operate and change images quickly, utilizing digital image technology not only to be ready to go, but also to modify the image content and text information separately