align_image_stack fails to process PNGs: Assertion failed

[unfa]

align_image_stack fails for certian PNG files that were created by ImageMagick convert from a CorelDRAW-created PDF file.

Here's the commandline output:

Unable to read EXIF data from opened file:C47C_ref.png
Unable to read EXIF data from opened file:C47C_src.png
Creating control points between C47C_ref.png and C47C_src.png
align_image_stack: /build/hugin-xzKV1g/hugin-2015.0.0+dfsg/src/tools/align_image_stack.cpp:740: int main2(std::vector<std::__cxx11::basic_string<char> >, Parameters) [with PixelType = vigra::RGBValue<unsigned char>]: Assertion `nextImgInfo.size() == firstImgInfo.size()' failed.

Sometimes it works, sometimes it doesn't. I tried converting the files back and forth to different formats to drop any strange data that could confuse align_image_stack, but it kept failing to process the files.

Is this a bug?

[tmodes (tmodes)]

Align_image_stack expects that all images have the same size. So you have probably feed different sized images to it.

The current version prints in this case a better error message:
Images have different sizes.
C47C_ref.png width x height pixel, while
C47C_ref.png has width2 x height2 pixel.
This is not supported. Align_image_stack works only with images of the same size.

[tmodes (tmodes)]

The warning was not correctly displayed. This is now fixed in repository.