Legacy ImageMagick Discussions Archive

How can I determine the colour depth of an image in bits-per-pixel?

I expected it to be a no-brainer with a simple identify, but was wrong. For example, this is what an identify output of a 24-bpp JPEG looks like:

logo.jpg JPEG 640x480 640x480+0+0 DirectClass 8-bit 88.0859kb

Notice the 8-bit (!) part. identify -verbose also refuses to list a nice and plain "24" anywhere... Am I overlooking something here?

Identify -verbose lists your image depth. For example:

• Channel depth:
  Red: 8-bit
  Green: 8-bit
  Blue: 8-bit
  Channel statistics:
  Red:
  Min: 0 (0)
  Max: 255 (1)
  Mean: 228.364 (0.895545)
  Standard deviation: 70.8226 (0.277736)
  Green:
  Min: 6 (0.0235294)
  Max: 255 (1)
  Mean: 229.059 (0.898272)
  Standard deviation: 62.94 (0.246824)
  Blue:
  Min: 10 (0.0392157)
  Max: 255 (1)
  Mean: 232.288 (0.910932)
  Standard deviation: 55.8149 (0.218882)

I noticed those information of course ... so, I gather from your answer that I'll have to calculate the overall bits-per-pixel depth myself from #channels x bits-per-channel, and that I cannot grab (or, grep ) that from identify's output directly. Right?