Image blending method, projection system and processing device thereof

A projection system, comprising:

• a first projector, a second projector, a third projector, an image cropping device, and a processing device, wherein:
• the image cropping device is connected to the first projector, the second projector, and the third projector;
• and
• the processing device is connected to the image cropping device, wherein the image cropping device is configured to, according to a projection instruction of the processing device, transmit an image data corresponding to the projection instruction to the first projector, the second projector, and the third projector,
• wherein the first projector projects a first image onto a projection surface according to a first image data, the second projector projects a second image onto the projection surface according to a second image data, and the third projector projects a third image onto the projection surface according to a third image data, wherein an image of a first portion of the first image and an image of a first portion of the second image projected onto the projection surface overlap each other in a first overlapping area on the projection surface, and an image of a second portion of the second image and an image of a first portion of the third image projected onto the projection surface overlap each other in a second overlapping area on the projection surface,
• wherein the processing device renders a first control pattern, and projects the first control pattern onto the first image through the image cropping device and the first projector, wherein the first control pattern is projected onto a first initial position in the first image, and the first initial position of the first control pattern does not match the first overlapping area,
• wherein after projecting the first control pattern, the processing device is further configured to adjust the first control pattern in the first image and move the first control pattern from the first initial position to the first overlapping area according to a first input operation applied to the processing device, such that a first control pattern frame of the first control pattern matches a boundary of the first overlapping area,
• wherein the processing device is further configured to identify a position of a first non-overlapping area in the first image according to a position of the matched first control pattern frame,
• wherein the processing device renders a second control pattern, and projects the second control pattern onto the second image through the image cropping device and the second projector,
• wherein the processing device is further configured to adjust the second control pattern in the second image according to a second input operation applied to the processing device, such that a second control pattern frame of the second control pattern matches the boundary of the first overlapping area,
• wherein the processing device is further configured to identify a position of a second non-overlapping area in the second image according to a position of the matched second control pattern frame,
• wherein the processing device renders a third control pattern, and projects the third control pattern onto the third image through the image cropping device and the third projector,
• wherein the processing device is further configured to adjust the third control pattern in the third image according to a third input operation applied to the processing device, such that a third control pattern frame of the third control pattern matches a boundary of the second overlapping area,
• wherein the processing device is further configured to identify a position of the third non-overlapping area in the third image according to a position of the matched third control pattern frame,
• wherein the processing device is further configured to adjust image parameters of all pixels of the first non-overlapping area and the second non-overlapping area according to the position of the first non-overlapping area and the position of the second non-overlapping area, such that a black-level brightness of a first non-overlapping image in the first non-overlapping area of the first image and a black-level brightness of a second non-overlapping image in the second non-overlapping area of the second image are close to a black-level brightness of a first overlapping image in the first overlapping area, and the processing device is further configured to adjust image parameters of all pixels of the second non-overlapping area and the third non-overlapping area according to the position of the second non-overlapping area and the position of the third non-overlapping area, such that the black-level brightness of the second non-overlapping area in the second non-overlapping area of the second image and a black-level brightness of a third non-overlapping image in the third non-overlapping area of the third image are close to a black-level brightness of a second overlapping image in the second overlapping area, wherein the black-level brightness of the third non-overlapping image is adjusted to be close to the black-level brightness of the first non-overlapping image and the second non-overlapping image.