when writing tiled tiff, tile size must be multiple of 16 (?)

[kaczmarj]

hi, thanks for this excellent software! i am using multiresolutionimageinterface to write a tiled tiff image (for the TIGER challenge). i am attempting to write some tiles, but when i apply writer.finishImage(), i get an error that no valid tiles are written. after some debugging, turns out that the writer's tile size needs to be a multiple of 16. i'm wondering if this is indeed the case?

the libtiff docs write that the tile size needs to be a multiple of 8. but using the writer, i could only get multiples of 16 to work (eg tile size of 24 does not work). (excerpt of manpages below)

TIFFTAG_TILELENGTH              1      uint32             must be a multiple of 8
TIFFTAG_TILEWIDTH               1      uint32             must be a multiple of 8

the part of the code that returns the error is below.

ASAP/multiresolutionimageinterface/MultiResolutionImageWriter.cpp

Lines 319 to 322 in 33f3388

	if (TIFFIsTiled(_tiff) == 0) {
	std::cout << "No valid tiles have been written to the base image, cannot finish image." << std::endl;
	return -1;
	}

according to that error, the image data is organized in strips instead of tiles (from libtiff manpages).

TIFFIsTiled returns a non-zero value if the image data has a tiled organization. Zero is returned if the image data is organized in strips.

here is an example to reproduce this issue. i am using ubuntu 20.04 with asap 2.0.0 from the github releases of this project.

import multiresolutionimageinterface as mir
import numpy as np

def get_writer(output_path, tile_size, dimensions, spacing):
    writer = mir.MultiResolutionImageWriter()
    writer.openFile(str(output_path))
    writer.setTileSize(tile_size)
    writer.setCompression(mir.LZW)
    writer.setDataType(mir.UChar)
    writer.setInterpolation(mir.NearestNeighbor)
    writer.setColorType(mir.Monochrome)
    writer.writeImageInformation(dimensions[0], dimensions[1])
    pixel_size_vec = mir.vector_double()
    pixel_size_vec.push_back(spacing[0])
    pixel_size_vec.push_back(spacing[1])
    writer.setSpacing(pixel_size_vec)
    return writer

# Works
tile_size = 16
writer = get_writer("/tmp/foo.tif", tile_size=tile_size, dimensions=(4096, 4096), spacing=(0.5, 0.5))
tile = np.zeros((tile_size, tile_size), dtype="uint8")
writer.writeBaseImagePartToLocation(tile.flatten(), x=0, y=0)
writer.finishImage()

# Does not work, even though this is multiple of 8.
tile_size = 24
writer = get_writer("/tmp/foo.tif", tile_size=tile_size, dimensions=(4096, 4096), spacing=(0.5, 0.5))
tile = np.zeros((tile_size, tile_size), dtype="uint8")
writer.writeBaseImagePartToLocation(tile.flatten(), x=0, y=0)
writer.finishImage()

[alessiamarcolini]

Dear Maintainers, I have the same issue. Can you comment on this?

[464hee]

Have you solved it? I have encountered similar problems