Projection method, processing apparatus, projection system, and recording medium

The invention provides a projection method, a processing device, a projection system and a recording medium, which can improve user convenience in adjustment of projection images projected by a plurality of projectors. The projection method includes: when a first adjustment including shape correction of a first projection image projected by a projector is executed, updating a first setting value for shape correction of the first projection image by accepting an operation for changing the shape of the first projection image; and projecting, from the projector, a third projection image in which the shape of the first projection image is corrected on the basis of the first setting value and the brightness of an overlapping region in the first projection image is not corrected, the overlapping region is a region where the first projection image overlaps with a second projection image projected by another projector different from the projector. 提供投射方法、处理装置、投影系统和记录介质，能够在多个投影仪投射的投射图像的调整中提高用户的便利性。投射方法包含：在执行包含投影仪所投射的第