3. Resolution and image effects
The size of the resolution determines the degree of detail of the image recorded by the scanner. A higher resolution can improve the quality of the image, but this is limited. Unreasonably increasing the resolution will only increase the length of the image file. Large, does not produce a significant improvement in the quality of the image. What needs special attention is the difference between optical resolution and interpolation resolution: Optical resolution is a key factor in determining image sharpness and is limited by the scanner's hardware specifications; while the interpolation resolution is artificially increased by software, it is actually Did not add any image details.
The same large number of pixels can occupy different sizes in the output device. Under the same visual distance and condition, if the number of pixels is not changed, the image with small area shows a higher image sharpness, or it feels that the clarity is relatively high. Conversely, under the same visual conditions, as many pixels occupy too much area, it will affect the clarity of the image.
4. Resolution and output
Before choosing the scanning resolution, you must first check the condition of the output device, because regardless of whether the image is displayed on the screen or printed on paper, there are resolutions related to the output device only when the resolution of the image and the output device Matching the resolution for best results. If it does not match, one of the following two results will appear:
1) If the resolution of the image is lower than the resolution of the output device, the display or printing process will interpolate the extra pixels needed, and the final result will cause the image to lose some detail and sharpness.
2) If the resolution of the image is higher than the resolution of the output device, the display or printing process will discard extra pixels. This result is slightly better than the first result.
How to determine the ideal resolution? The ideal situation is that the scanning resolution matches the resolution of the output device to be used. Although the display resolution may be different from 72dpi to 96dpi, the change range is not large, and the printer's range of change is relatively large. The resolution of common inkjet printers has a wide range of variations, such as the Canon BJC-8200 color spray. The highest resolution of the ink printer is 1200dpiXl200dpl other models S900, S6300, S750, etc. The highest resolution can reach 2400dpiXl200dpi. The ideal resolution setting used for further scanning also depends on the relative size of the original and the replica. If you plan to copy the image in the same size as the original, there is no need for adjustment and you can scan directly at the resolution of the output device. However, if you want to display or print in different sizes, whether larger or smaller than the original, you need to make subtle settings when scanning.
As can be seen from the above description, the resolution not only affects the image quality, file length, but also affects the ease of operation, degree, file transfer time and output quality and many other aspects. Scanning at a resolution higher than required will lose valuable time and use up system resources excessively. Excessive file length requires more memory for image processing and more hard disk space for file storage. Adding this extra time and storage space to the amount of work in the image processing process, you will feel how amazing this waste is.
Therefore, it can be said that adjusting the resolution of the image to match the physical size of the output image is one of the most important tasks in preparation for scanning.
(to be continued)