title: Lossless YCbCr Tiff?
body: <p>My goal is to create a Tiff image that natively holds uncompressed (or with lossless compression) YCbCr data inside (since the original image is YUV420 and IMO it would be a poor choice to upsample and convert to RGB).
  I’m able to create (using imagemagick for instance) a valid YCbCr Tiff with a JPEG compressed data. When I try uncompressed / deflate / lzw I get a broken image (neither windows image viewer nor photoshop can open it). On page 94 of the TIFF 6.0 spec (under “Minimum Requirements for YCbCr Images”): </p>
  
  <blockquote>
    <p>Compression = none (1), LZW (5) or JPEG (6). SHORT.</p>
  </blockquote>
  
  <p>What’s wrong? Is there a Tiff extension which says that YCbCr color space is supported only when using jpeg compression?</p>
  
  <p>Thanks,
  Mark.</p>
  
  <hr>
  
  <p>Command that works:</p>
  
  <pre><code>convert infileRGB.tif -colorspace ycbcr -compress jpeg outfileYCbCr.tif
  </code></pre>
  
  <p>Commands that don't work (broken tiff):</p>
  
  <pre><code>convert infileRGB.tif -colorspace ycbcr -compress none outfileYCbCr.tif
  convert infileRGB.tif -colorspace ycbcr -compress lzw outfileYCbCr.tif
  </code></pre>