embed error

[mikemliu]

Getting an error embedding png with transparency on the default black background (inside larger background canvas)

start with a 50x50 png with alpha channel:

sharp(in)
.resize(50, 256)
.embed()
.pipe(out)

i get the following:

Error: linear: vector must have 1 or 4 elements

The following DO work:

• embedding a png with no transparency
• embedding on a background that matches the source aspect ratio

[mikemliu]

Flatten seems to resolve the issue:

sharp(in)
.resize(50, 256)
.flatten()
.embed()
.pipe(out)

[lovell]

Looks like a bug, thanks for reporting this. I'll try to add a test case to confirm this later today.

Were you hoping to preserve transparency in the output image?

[lovell]

I've reproduced this @mikemliu. It occurs when embedding an image with an alpha channel onto any background colour that does not have a transparency, which includes the default.

I've added a new test case to expose the failure and the fix in commit 33782d3.

Are you able to retest via npm install lovell/sharp?

[mikemliu]

I realized the same when I actually put in my desired transparent background. Thanks!

[lovell]

@mikemliu Were you able to confirm this fix solved the problem? If so I'll publish a point release with it to npm.

[mikemliu]

confirmed. thanks!

[lovell]

This is fixed in v0.10.1, now available via npm.