Selectable registration resolution

[krupkat]

Add an option to select registration resolution (in MPx) for the stitching algorithm. The images are downscaled to this size for finding matches between images.

The default value is 0.6MPx and that could be an issue e.g. if stitching two photos with electrical wires spanning over both of them.

Howto

• add a registration_resolution in:

  xpano/xpano/algorithm/options.h

  Line 82 in dee2e45

  struct StitchUserOptions {

• call SetRegistrationResolution in

  xpano/xpano/algorithm/algorithm.cc

  Line 232 in dee2e45

  StitchResult Stitch(const std::vector<cv::Mat>& images,

• Add a a widget in the gui for selecting the value (maybe ImGui::SliderFloat):

  xpano/xpano/gui/panels/sidebar.cc

  Line 301 in dee2e45

  Action DrawStitchOptionsMenu(pipeline::StitchAlgorithmOptions* stitch_options,

Stretch goal

Find / take some pictures where this effect can be demonstrated and add them to the PR.