• VEGAS Pro

  Cropping 4K footage to maintain 1:1 pixel mapping,

  Posted by John Schuermann on December 5, 2014 at 4:39 pm

  Hello all – my first post here. Hopefully someone can help me out!

  I have some 4K RED footage on the timeline. I want to crop a small 960 x 1080 section of the footage and render out to 960 X 1080 while MAINTAINING 1:1 PIXEL MAPPING. In other words, a straight crop, no scaling applied whatsover in the output footage (rendered to uncompressed).

  Next, I want to take a second copy of the same exact cropped footage (960×1080), scale it down by 25% to achieve a resolution of 960 x 810 while MAINTAINING THE ASPECT RATIO. I want to then take a second pass at this reduced resolution clip to scale it back up to 960 x 1080 and render it out, again MAINTAINING THE ASPECT RATIO. Like the first clip, I will render this out at 960 X 1080 uncompressed, but unlike the first clip this one will have undergone two scaling passes before the render.

  The last step is to import these two clips onto a 1920 x 1080 timeline and render them out side by side. QUESTION – if I use Track Motion to place the two 960 x 1080 clips side by side (thereby creating a split screen 1920 x 1080 clip), will I still maintain 1:1 pixel mapping? Maintaining the 1:1 mapping is critical here, especially for the unscaled clip.

  (In case anyone is wondering why the heck I would want to do this, the company I consult for is proposing a method for maintaining 1:1 vertical pixel mapping for Scope (2.40:1) content on next generation UHD Blu-ray / high quality digital media. This works by “hiding” extra resolution information behind the black letterbox bars that can be re-integrated into the Scope footage when displayed on 21:9 flat panels or anamorphically equipped projection systems. The point of this test is to show the improvement in resolution / picture detail achieved when 1:1 pixel mapping is maintained when transferring Scope content. Normally there is a 25% vertical resolution reduction that comes when you force 2.40:1 content into a 16:9 container space with letterbox bars.)

  Thanks to anyone for ideas how to do this! I know I can set up a 960 x 1080 project and find my crop, but the “stretch image to fill frame” option in the Crop / Pan dialogue makes me nervous, and I’m not sure I am maintaining image integrity from a pixel mapping perspective.

  Thanks for any thoughts, ideas or comments!

  John Schuermann replied 11 years, 9 months ago 1 Member · 0 Replies
• 0 Replies

Reply to this Discussion! Login or Sign Up