Method for discriminating focus quality of image pickup device
A focus-quality judging method includes the following steps. Firstly, a comparing object including a target area is provided. A reference image pickup device is provided to shoot the comparing object to obtain a standard image including a standard target area image. Then, a first pixel number contained in the standard target area image is counted. The comparing object is shot by a test image pickup device to obtain a test image including a test target area image, wherein the test image has the same resolution as the standard image. Then, a second pixel number contained in the test target area image is counted. The first pixel number contained in the standard target area image is compared with the second pixel number contained in the test target area image. According to the comparing results, it is discriminated whether the test image pickup device performs an accurate focusing operation.
1. A focus-quality judging method for discriminating focus quality of a test image pickup device, said focus-quality judging method comprising steps of:
providing a comparing object including a target area;
providing a reference image pickup device to shoot said comparing object to obtain a standard image including a standard target area image;
using a computer to count a pixel number P 1 contained in said standard target area image;
shooting said comparing object by said test image pickup device to obtain a test image including a test target area image, wherein said test image has the same resolution as said standard image;
using the computer to count a pixel number P 2 contained in said test target area image; and
using the computer to compare said pixel number P 1 contained in said standard target area image with said pixel number P 2 contained in said test target area image, wherein if P 2 is more than or equal to P 1 , said test image pickup device is deemed to perform an accurate focusing operation, or if P 2 is less than P 1 , said test image pickup device is deemed to perform an erroneous focusing operation.
2. The focus-quality judging method according to claim 1 wherein both of said standard image and said test image are captured at resolution of 800×600.
3. The focus-quality judging method according to claim 1 wherein said reference image pickup device and said test image pickup device are cameras, digital cameras or video cameras.
4. The focus-quality judging method according to claim 1 wherein said comparing object is a photo, a paper or a document, and said target region is a picture included in said comparing object.
5. A focus-quality judging method for discriminating focus quality of a test image pickup device, said focus-quality judging method comprising steps of:
providing a comparing object including a target area;
providing multiple reference image pickup devices D 1 ˜D N to shoot said comparing object to obtain multiple standard images I 1 ˜I N , wherein said standard images I 1 ˜I N have respective standard target area images T 1 ˜T N ;
using a computer to count pixel numbers P 1 ˜P N contained in respective standard target area images T 1 ˜T N ;
using the computer to calculate an arithmetic mean P′ 1 of said pixel numbers P 1 ˜P N contained in respective standard target area images T 1 ˜T N ;
shooting said comparing object by said test image pickup device to obtain a test image including a test target area image, wherein said test image has the same resolution as said standard images;
using the computer to count a pixel number P 2 contained in said test target area image; and
using the computer to compare said arithmetic mean P′ 1 of said pixel numbers P 1 ˜P N contained in respective standard target area images T 1 ˜T N with said pixel number P 2 contained in said test target area image, wherein if P 2 is more than or equal to P′ 1 , said test image pickup device is deemed to perform an accurate focusing operation, or if P 2 is less than P′ 1 , said test image pickup device is deemed to perform an erroneous focusing operation.
6. The focus-quality judging method according to claim 5 wherein all of said standard images and said test image are captured at resolution of 800×600.
7. The focus-quality judging method according to claim 5 wherein said reference image pickup devices and said test image pickup device are cameras, digital cameras or video cameras.
8. The focus-quality judging method according to claim 5 wherein said comparing object is a photo, a paper or a document, and said target region is a picture included in said comparing object.