Viewing Professional Scanner Selection from Software Technology (Part 2)

Due to the professional scanner's requirements for image resolution, color gradation, scanning speed, scan format, and other basic functions, as well as post-processing and color correction of scanned works, the requirements are high. Therefore, professional scanners not only generally contain a large number of latest technologies and latest technologies, but also have higher standards and complex requirements on their traditional technologies. These basic technologies mainly include color management and correction, bit enhancement, intelligent scanning, and hardware. Go to netting and other technologies, let's introduce the main connotations of these basic technologies.

In the professional production fields such as prepress systems, advertisements, and graphic images, users are not only concerned with the scanner's hard resolutions such as optical resolution and color description, but also people are concerned about the unique technology and performance of each scanner product. They may become an important basis for professionals to choose a scanner. The following describes several technologies that are designed to accommodate designers who care about colors.

1. Color management and correction technology

Each scanner has its own color management system and color correction function, especially professional scanners not only have high optical resolution, but also have advanced and perfect color management and correction system, which can be completed with limited physical resolution. Natural color entry.

The so-called color management is to make the scanned image color full, vivid and realistic, to reduce the purpose of color distortion. Color management technology is generally reflected in the color characteristic values ​​(ICC) of a range of other devices built into the scanner driver software, such as printers, displays, and ink type settings. Through the driver software's own color system standard (high-end professional scanners mostly use HSB, HLS and other neutral color systems) to calibrate the scanner output image, its main purpose is to try to achieve WYSIWYG to simplify the use of The complex correction process saves time for manually correcting the color of each scanned image, increasing the scanning efficiency and the scanning speed. At the same time, in order to ensure the accuracy of the output color, the driver software of the general high-end professional scanner also provides a color separation table, which provides the important settings required for color separation, if the GCR and UCR settings, tone range calibration, CMYK four-color Dot gain settings and ink type settings.

The basic principle of color correction technology is that the scanner first scans IT-8 color chips such as dedicated KODAK or AGFA, and then compares the color recognition performance of the scanner with its standard value to obtain the average color deviation. The color profile (ICC) of the scanner is formed, and the color calibration of the scanner is performed through the profile during each scan of the scanner to achieve the best performance of the scanner. Therefore, it is beneficial for scanner users to regularly perform color correction because the scanner's color correction is based on the user's current scanner's recognition performance. In the scanning process, the performance of the scanner may be degraded due to aging and other issues. , and regular color correction can make the user's scanner maintain good scanning quality. Some modern professional scanners also use dynamic color correction technology. This kind of instant clinical correction technology makes the scanning results closer to the original. The technical feature is that when the scanner is working, the scanning results can be directly with the standard color values. Dynamic comparison, and obtain the state data that this scanned image needs to compensate, thus greatly improving the quality and scanning speed of the scanned image. Obviously, the professional scanner's color management system and color correction system are not only perfect, but also very powerful.

2. "bit enhancement" technology

The sensitometric curve of the human eye is inconsistent with the sensitometric curve of the scanning sensor. Since the scanner is a precision electromechanical device, the sensitometric curve is linear, and the sensitometric curve of the human eye is a complex curve, and the sensitivity to the details of the shadow is obvious. Higher than the sensor. If the data information obtained by the sensor is transmitted intact to the person's eyes, the image will be significantly distorted, so more and more professional scanners use correction techniques. However, the use of calibration technology means that the sensor must acquire more data than the commonly used 24-bit true color, so a 36-bit, 42-bit, or even 48-bit professional scanner appears so that more reference can be obtained during calibration. Click to improve the accuracy of the scanned image. However, a significant increase in optical resolution will inevitably lead to a substantial increase in the price of the scanner. Therefore, for the 36-bit professional scanners, the relevant strong technology is generally used to indirectly improve the scanning quality of the scanner.

3. Intelligent scanning technology

Intelligent scanning technology mainly includes dual-resolution scanning technology, automatic analysis technology for complex pages, enhanced graphics technology, reserved page format, and 1200dpi hardware supersampling technology and 36-bit color processing technology. The dual-resolution scanning technology can obtain two versions of the same document in one scan, and each version can be optimized according to different image types. Since two versions are obtained in one scan, the user can quickly be satisfied As a result, the scanning speed and the recording efficiency are greatly improved. Automatic analysis of complex pages means that the appropriate resolution, color depth, and file format are set according to the type of image and the selected purpose of the entire page. The automatic complex page analysis scanner can be performed in a simple scanning stage. Complete multiple local processing, and can automatically identify the text, photos, graphics on the page, according to the image type on the rational optimization of each image block for the user to select the destination to send each image block and file format.

Enhanced graphics technology can intelligently adjust image distortion or “jaggies” caused by scanning the background or scanning scale, optimize black and white logos and graphics, and obtain scanned images that are often larger than originals. Clear and tidy. In the image scanning, enhanced graphics technology can also optimize the picture on the page, provide automatic exposure, automatic sharpening function, and optimize according to the printer. For text or OCR documents, enhanced graphics technology can also produce more accurate OCR recognition rate and more perfect conversion function, can complete infinite font size recognition, can retain font and size, preserve italics, bold and underline features, retain The page format can convert text to software missing fonts. Intelligent scanning technology can also convert black and white graphics files into vector files, which can make the user files without any reduction in image quality when any zoom, creating unconstrained scanning resolution. Therefore, in specialized scanners with special requirements, smart scan technology can be used to receive even more powerful results.

4. Intelligent hardware de-networking technology

The principle of the hardware de-networking function is to decompose the whole image into many small squares. Each grid size is the same as the size of the dot, and then the data in the opposite grid is averaged, and the image can be restored to a photo effect. Remove dot functionality. Obviously, the perfect condition for this function to be perfectly implemented is that the squares correspond to the outlets one by one, and no overlap occurs. However, because the built-in position of the scanner is fixed and the randomness of the position of the original is scanned, misalignment and coincidence of the grid and the dot are often caused, and the neighboring points are averaged together so that the image loses its sharp border. In the field of intelligent hardware de-internet technology, a network of images is scanned to generate a set of electrical signals representing the strength of the signal, and each of the network points becomes an electrical pulse. The widths of these electrical pulses are different, representing the size of the dots, and the distance between the centers of the two electrical pulses is constant. As long as the distance between every two electrical pulses is precisely detected and three electrical pulses are used as the reference point, the density of the dots can be accurately determined, and the grid can be accurately meshed with the dots to achieve the ideal The effect of the net to get a clear scan image.

5. Other professional scanning new technologies

In professional scanners, in order to maximize the scanning performance, a large number of new technologies and new functions have been adopted. Among them, the optimization of the scanning speed is a software function, but it enables the scanner to automatically provide the Fast data transmission can ensure the user to scan at the optimal speed. Dual lens technology is a new technology that uses two CCD sensors to achieve two different optical resolutions. The principle is to change the lens focal length to increase the fixed optical resolution of the scanner. Parallel scanning technology allows the scanner to read rgb data at the same time, which is more than three times faster than a typical scanner. It is very important for large-information scanning tasks in professional scanning systems. Super-removal lens system is a kind of precision. The professional optical design system, but it can eliminate the chromatic aberration of the imaging edge to the maximum extent, prevent the image from blurring, and even provide the most clear image without color aberration even at the highest resolution; micro stepping drive technology can precisely control the scan head displacement , can improve the scanning accuracy and sharpness, reduce the instability caused by sawtooth Pattern and color distortion; dynamic range control technology can automatically adjust and reconstruct the dynamic range of the image, greatly improving the lack of dark layers and black artifacts in the scanning; simultaneous RGB scanning technology changes the previous lens to scan RGB separately The recombination method makes it possible to synchronize RGB scans to ensure that RGB can be reflected on the same spot on the CCD, reducing color distortion.

Source: Tianji.com