What are pixels, maximum and effective pixels?

What are pixels?

Pixels are composed of small squares of images, so-called pixels, which have a clear position and assigned color values, And the color and position of these small squares determine what the image looks like.

Maximum Pixels

The so-called maximum pixels are obtained from the interpolation operation. When you need to enlarge the image, you can use the nearest neighbor, linear interpolation or other computer methods through the internal DSP chip. And then add the required pixels after enlarging pictures.

The image quality of interpolation can not be compared to actually photograph.

With the same principle, some manufacturers will mark that "It can up to xxx pixels by hardware interpolation." in the market. However, the pictures shot by the maximum pixels which don't match for effective pixels in the sharpness.

The maximum pixels also refer to the CCD / CMOS sensor pixels, some manufacturers advertised the largest pixels for more deals. And it does can take the photos at the highest resolution, but the buyer should know that it got from the internal operation, the impairment of its quality will be very obvious.

Effective Pixels

The effective pixels refer to the real pixels involved in photographic imaging, which is zoomed out in the lens zoom value. Take Minolta DiMAGE7 for example, the CCD pixels is 5.25MP, but some of the pixels do not take part in imaging, the effective pixels are 4.9MP. Therefore, in the same pixel area, the camera can get the largest pixels, that is effective pixels.

Interpolation

Interpolation is a method of redistributing the pixels of the original picture, thereby to change the number of pixels. In the process of image enlargement, the pixels also increase accordingly - this is the process the interpolation. Interpolation program automatically selects the better pixels to make up the black space, not just nearby pixels, so that the enlarged image will be sharper and smooth.

However, it should be noted that the interpolation does not increase the image information, although the size of the image becomes larger, the image quality will be relatively vague.