I'm trying to join multiple images together using pyvips, but during the process the width of the image more than doubles, and I can't seem to figure out why
Here's the key part of my code:
files = ['small_images\\'+filename for filename in os.listdir('small_images')]
files = natsorted(files)
images = [pyvips.Image.new_from_file(filename, access="sequential") for filename in files]
[print(f'width: {image.width}, height: {image.height}') for image in images]
raster = pyvips.Image.arrayjoin(images,across=len(images))
print(f'raster width: {raster.width}, raster height: {raster.height}')
raster.write_to_file(f'rasters.png')
Expected output for 5 files should be:
width: 115, height: 1449
width: 44, height: 1449
width: 226, height: 1449
width: 74, height: 1449
width: 35, height: 1449
raster width: 494, raster height: 1449
But my actual output is:
width: 115, height: 1449
width: 44, height: 1449
width: 226, height: 1449
width: 74, height: 1449
width: 35, height: 1449
raster width: 1130, raster height: 1449
Images: https://i.sstatic.net/bCqPV.jpg
What's causing this?
arrayjoin only does regular grids of images -- it'll pick the maximum width and height in your set of images, and that becomes the spacing. It's like a table layout.
If you want to join a series of images of varying width left to right, you need to do a series of joins. For example:
output = images[0]
for image in images[1:]:
output = output.join(image, 'horizontal', expand=True)
You can set alignment, spacing, background, etc., see:
https://libvips.github.io/libvips/API/current/libvips-conversion.html#vips-join