from ijutils import *


def before_read(position, scan):
    ProviderTIFF.setMetadata({"index": scan.recordIndex})


num_images = 4
r=tscan((sin, det.dataMatrix), num_images, 0.1, before_read=before_read)

data_folder = expand_path("{data}/" + r.path.replace(" | ", "/"))

imgs_per_row=2
imgs_per_col=num_images/2

combined_image = None
for i in range(num_images):
    filename = data_folder + ("/%s_%04d.tiff" % (det.dataMatrix.getName(),i,)) 
    img = ImagePlus(filename)
    proc=img.getProcessor()
    if not combined_image:    
        combined_image = ImagePlus("Combined Image", proc.createProcessor(proc.getWidth()*imgs_per_row, imgs_per_col * proc.getHeight()))
    x,y = i%imgs_per_row,  i/imgs_per_row
    combined_image.getProcessor().insert(proc, x * proc.getWidth(), y * proc.getHeight())

filename = data_folder + ("/%s_combined.tiff" % (det.dataMatrix.getName(),))
save_image(combined_image, filename, "tiff", metadata={"index": -1})