Image forming method and apparatus for using black-and white camera to capture color image

An image forming method for using black-white camera to capture color image, comprising the following steps:

• (1) utilizing a red LED light, a green LED light, and a blue LED light as source of light, for emitting and irradiating directly on imaging object (4) with composite lights of any two colors as chosen from red light, green light, and blue light in a rotation manner;
• (2) forming images of an object (4) on a light sensing chip (6) of a camera through an optical lens (5), processing by peripheral circuits of the images received by the light sensing chip (6) of a camera into digital image information and transmitting it to a processor (PC), thus obtaining at the same position on said processor (PC) the following images in an environment of composite lights of three colors:
• red plus green gray level image (11), green plus blue gray level image (12), and blue plus red gray level image (13);
• (3) for a gray level value (i1) of a position corresponding to said red plus green gray level image (11), a gray level value (i2) of a position corresponding to said green plus blue gray level image (12), and a gray level value (i3) of a position corresponding to said blue plus red gray level image (13), performing the following calculation processes for the respective points on an image by means of an image synthesis & calculation processing module, in obtaining red component value (r), green component value (g), and blue component value (b) of the present position through the following formulas, thus obtaining a color image having its saturation and illuminance fulfilling the requirements,
• the formulas mentioned above are as follows:
• i1=r+g
• i2=g+b
• i3=b+r
• a1=(i1+i2+i3)/2
• a2=s*(i1−i2)
• a3=s*(i1−I3)
• r=gain*(a1+2*a2−a3)/3
• b=gain*(r−a2)
• g=gain*(a3+b)
• wherein, said s is a saturation regulating factor, with its range 0.5-3;
• said gain is an illuminance gain, with its range 0.5-3;
• and
• said a1, a2, and a3 are assumed parameters;
• (4) upon setting saturation gain and illuminance gain, proceeding with white balance of color imaging;
• firstly, taking color image of standard gray level color card (7), then calculating an average illuminance of said red component value (r), said green component value (g) and said blue component value (b) of an entire color image, and finally regulating illuminance of light source through a light source luminous intensity regulating circuit, so that said red component value (r), said green component value (g), and said blue component value (b) are essentially the same, then terminating regulation and locking onto the light source luminous intensity regulating circuit, hereby finishing white balance of color imaging;
• and
• (5) when taking images of a real object again, thus being able to obtain high definition image having its color close to that of a real image, performing iteration in synthesizing color images for realizing real-time display effect.