For today's prepress digital information, standard digital image files are stored or opened using many different specifications, and can be transferred from one software to another, or from one platform to another. It is a necessary trend.
In the face of the color output methods of printing, proofing, faxing, etc., these images can provide objective assessment methods in image processing time, system performance, and image quality; they can also encode images and data. Compression ratio or data transmission efficiency is evaluated; in addition, characterization can be performed on printed products that have been subjected to conventional printing processes or digital direct output. The color reproduction system's color reproduction capability is good or bad, there are two ways to judge. One is to subjectively evaluate the final output image (favorite color); the second is to make an objective assessment based on the colorimetric instrument measurement results.
Standard color images can be roughly divided into natural images and non-natural images. Natural images contain high-resolution images such as fleshtones, high bright colors, dark colors, neutral colors, difficult-to-replicate tree colors, memory colors, and complex geometric shapes. Unnatural images include resolution charts, color charts, arabesques drawn from primary and secondary colors, and CMYK four-primary printed images.
All standard color images are divided into two digital encoding methods. In the first encoding method, the resolution of the image is 16 pixels per millimeter, the coded value is 28 for the 0% print value (black), and 228 is the 100% print value (white). In the second encoding method, the resolution of the image is 12 pixels per millimeter, the coded value is 0 for the 0% print value (black), and 255 is the 100% print value (white).
After the above-mentioned encoding process, the resulting digital information can be accessed on the CD-ROM. The file format is TIFF/IT file (ISO12639).
Standard color image features
For the use of standard color images, there are the following characteristics:
(A) can confirm the amount of data
The minimum unit of the digital image is a bit, and by adding up the number of bits, it can be confirmed whether an image is completely converted or restored before and after the image processing.
(b) Color sequences
Any color point in the image, whether it is to be printed out or stored in a data file, can be controlled.
(c) Color values
That is, each pixel in the image is assigned a specific position and color value, which is represented by a Numeric method. The usual setting is 8 bits per pixel, that is, 256 colors. For the quantified value, its range can be defined.
(d) Network Coverage Ratio
The ratio of the area covered by the dots in the image ranges from 0% to 100%. It is worth noting that the brightest part of the image has the smallest dot coverage, close to or equal to 0%, while the darkest part of the image has the highest dot coverage, which is close to or equal to 100%.
(5) Color changes in the overall image
The selected region of the image, the relationship between the change in the color value and the color value of the rest of the image. That is, the digital image can be modified for the specific color in the image.
(six) gray balance
In color reproduction, neutral colors can be achieved if the primary colors of the three primary colors are balanced. Neutral grays give rise to color casts that are easily noticeable because the human eye is particularly sensitive to grey feelings. When the image is processed, where the neutral color value and the neutral color value of the replica are the same, the hue balance of the color reproduction can be considered correct.
(seven) color scanner (color signal source)
A color scanner can read photos into electronic digital signals through the reflection or transmission of light on the photos. These digital signals are related to the spatial domain of the overall image.
(8) Reading direction
The contents of the standard color image are read in the right-reading mode.
(IX) Pixels
Pixel is composed of two characters, Picture and Element. It is a unit used to calculate digital images. Like digital photographs, digital images also have a continuous dark tone. If you enlarge the image several times, you will find that these continuous colors are actually composed of many small squares with similar colors. These small squares are the images that make up the image. The smallest unit of "pixels."
Image resolution is expressed in pixels per inch (pps). When the image is printed or output, the number of points and resolution of the image will determine the height and width that appear on the print file. Therefore, for an image with the same number of points, the higher the resolution, the smaller the printed image will be.
(10) In the pixel, the composition order of numerical values ​​of cyan, magenta, yellow and black
In the image, the sequence of the combinations of the cyan, magenta, yellow, and black inks for each pixel is the same as the next adjacent pixel.
(11) Threshold
Threshold of the gray level of the image is grouped by the gray level of the image. Generally, the gray level divides the image into two gray levels.
Any image that requires text recognition or stripe recognition can use this method to simplify a complicated drawing. Therefore, how to select the appropriate and correct threshold value is an important task.
We have a wide variety of wall clocks in different sizes and functions. They are rounded collections and other irregular shape collections. which are all very easy for using but very attractive. They are made of different material like metal wall clocks, plastic wall clocks and wood wall clocks and etc. These decorative wall clocks all can be placed in your office or living room to make life more fashionable and work more interesting. What`s more, we have the perfect after-sales service and technical support. Some of them are always have production in stock so that you can place a small trail order. Look forward for your cooperation!
Wall Clock,Metal Wall Clock,Retro Wall Clock,Plastic Wall Clock
Guangzhou Huan Yu Clocking Technologies Co., Ltd. , https://www.mk-time.com