ImageAssemble
ImageAssemble[{{im11,…,im1n},…,{imm1,…,immn}}] assembles a single image from an array of images.
ImageAssemble[{{im11,…,im1n},…,{imm1,…,immn}},fitting] assembles images using the fitting method.
Please visit the official Wolfram Language Reference for more details and examples on core symbols.