Image determining method and object coordinate computing apparatus

An object coordinate computing apparatus pointing to an electronic apparatus having an object, the object coordinate computing apparatus comprising:

• a camera, for catching a gray level diagram for an image comprising at least one object image;
• a reading circuit, configured to scan the image and to determine which pixels in the image are object image pixels of the object image, wherein the reading circuit performs following steps:
• recording brightness values and coordinates for the pixels and determining at least one pixel in a first row of the image having brightness value larger than a threshold value as the object image pixel;
• defining a leftmost pixel and a rightmost pixel of the object image pixel in the first row as a leftmost edge and a rightmost edge of a first object image range;
• and
• defining a second object image range in a second row of the image, wherein the second row is next to the first row;
• wherein a column position of a leftmost edge of the second object image range is determined based on a column position of the leftmost edge of the first object image range;
• and
• wherein a column position of a rightmost edge of the second object image range is determined based on a column position of the rightmost edge of the first object image range;
• wherein the reading circuit further utilizes the recorded brightness values and the recorded coordinate to compute a gravity center of the object;
• wherein the object coordinate computing apparatus further comprises a processor configured to compute a displacement between the object coordinate computing apparatus and the object according to the gravity center and the recorded coordinates, and configured to control an operation of the electronic apparatus according to the displacement.