Pixels with the resolution, what is the difference?

1. What is a pixel? Put simply, we are usually talking about pixels, is the CCD / CMOS optoelectronic sensors on the number of components, a photosensitive element after photographic, photoelectric signal conversion, A / D conversion step, the output at the photo on the formation of a point, if we put the image to enlarge several times, you will find that these are in fact continuous tone color similar to those of many small parties consisting of points, which constitute a small side point is the smallest unit of image "pixels" (Pixel). CCD pixels are divided into pixels and effective pixels, is now on the market marked the majority of digital cameras are CCD pixels rather than an effective pixel.

2. What is the resolution? Speaking of pixels on the resolution had to talk about. Since the two are inseparable! The so-called "resolution" refers to units of length, the expression or the number of captured pixels. And pixel, the resolution also divided into many versions. One of the most common is the image resolution, we usually say that the output of digital camera photos maximum resolution, refers to the image resolution, units are ppi (Pixel per Inch) Print resolution is also very common, as the name implies, is the printer or printing equipment, the output resolution, unit is the dpi (dot per inch) Display resolution, is the Windows desktop size. Common settings have 640x480, 800x600, 1024x768 ... and so on. Screen font resolution: PC font resolution is 96dpi, Mac font resolution of 72dpi. Of course there will be other output device resolution. Because of a wide range, in this not described in detail, there is interest in a friend can go online search.

3. Pixel image resolution and the relationship between the That said, the definition of pixels and resolution, let us take a look at the relationship between the two. Friend may be careful has been found that pixel and resolution are directly proportional to, the greater the pixel resolution is also higher. Let us take an example! Previously mentioned, sub-pixel effective pixels and the CCD pixel Normally two million-pixel digital camera, the largest-resolution images are 1600 × 1200 = 192 million pixels, in other words, the actual effective pixels is 1,920,000. Commonly referred to as three million pixel digital camera, the largest-resolution images are 2048 × 1536 = 3145728 pixels, that is to say 3,140,000 effective pixels. Other-pixel digital camera, its effective pixel resolution and conversion is also true. Can be seen that the higher the pixels, maximum output is also higher resolution images.

4. Printing resolution and the relationship between pixel Print resolution, related to the size of our photo prints, and therefore more important. In fact, method of calculation is very simple: 2,000,000-pixel digital camera, 1.92 million effective pixels, maximum output of 1600 × 1200 Photos Wide: 1600 Pixels/300 dpi = 5.3 " High: 1200 Pixels/300 dpi = 4 " This means that if the output resolution of 300dpi prints, prints up to 5.3 × 4-inch photos, but usually the size of photos are: 5 inch: 5 × 3.5 6 inch: 6 × 4 It is clear that the two million pixels to 300dpi the effect of processing the largest 5-inch photos. (Note: The human eye can tell the maximum resolution is 300dpi, beyond this resolution, people's eyes are unable to see the difference, that is to say 300dpi and 600dpi people at a glance there is no difference, so now processing equipment The biggest design output resolution is 300dpi, of course, each person's request for clarity is not the same as, in general can achieve 200dpi will be able to let the majority of people satisfied with the two million so-pixel prints 6-inch photos, in most people it seems very clear.)

Summary: As mentioned above, the "print size" and the image resolution are closely related, as long as the image resolution has changed, the size of print will be followed by changes in pixel resolution and image have a direct relationship, so the three can be mutual conversion. And one of the most fundamental is the pixel.

So buy a digital camera, the pixel is also an important consideration, the specific needs of the number of pixels, can be according to their own needs.