4 channel LZW TIFF output returns a value of 3 for info.channels #2064
Description
System:
OS: Linux 4.15 Ubuntu 18.04.1 LTS (Bionic Beaver)
CPU: (8) x64 Intel(R) Xeon(R) CPU E3-1505M v6 @ 3.00GHz
Memory: 1.68 GB / 15.52 GB
Container: Yes
Shell: 4.4.19 - /bin/bash
Binaries:
Node: 12.10.0 - /usr/bin/node
npm: 6.12.0 - /usr/bin/npm
Utilities:
CMake: 3.10.2 - /usr/bin/cmake
Make: 4.1 - /usr/bin/make
GCC: 7.4.0 - /usr/bin/gcc
Git: 2.17.1 - /usr/bin/git
Subversion: 1.9.7 - /usr/bin/svn
FFmpeg: 3.4.6 - /usr/bin/ffmpeg
Languages:
Bash: 4.4.19 - /bin/bash
Go: 1.10.4 - /usr/bin/go
Perl: 5.26.1 - /usr/bin/perl
Python: 2.7.15+ - /usr/bin/python
Python3: 3.6.8 - /usr/bin/python3
Ruby: 2.5.1 - /usr/bin/ruby
I'm trying to create a 4-channel tiff from raw pixel data. Unfortunately, when this is written to disk, the image has only 3 channels. Here's snippet using sharp 0.24.0
import * as sharp from 'sharp'
async function main () {
const width = 32
const height = 32
const channels = 4
const info = await sharp(
Buffer.from(new Array(width * height * channels).fill(0)),
{
raw: { width, height, channels }
}
).toFile('test.tif')
if (info.channels !== channels) {
throw new Error(`Unexpected number of channels in output image. Expected ${channels}, but got ${info.channels}`)
}
}
main()
Issue also occurs when saving jpgs (eg toFile('test.jpg')). Does not occur saving pngs.
I can't see anything obvious in the docs that excludes this possibility. Advice appreciated.