possible bug -blur IM 7 HDRI vs IM 6 HDRI

[fmw42]

I am having a problem with -blur in IM 7.0.6.1 Q16 HDRI. It works fine in IM 6.9.8.10 Q16 HDRI. It seems to be in association with MPC format.

Note the ranges for the statistics for min and max after the blur.

IM 6 HDRI

Code: Select all

im6hdri convert logo: \
-define convolve:scale=50%! -bias 50% \
\( -clone 0 -morphology Convolve Sobel:0  \) \
\( -clone 0 -morphology Convolve Sobel:90  \) \
-delete 0 -solarize 50%  -level 50,0%  \
-compose Lighten -composite \
-separate -evaluate-sequence Max \
-auto-level +write tmpA6.mpc \
-blur 0x20 tmpB6.mpc

Code: Select all

im6hdri identify -verbose tmpA6.mpc
Image: tmpA6.mpc
  Format: MPC (Magick Persistent Cache image format)
  Class: DirectClass
  Geometry: 640x480+0+0
  Units: Undefined
  Type: Grayscale
  Endianess: Undefined
  Colorspace: Gray
  Depth: 8/16-bit
  Channel depth:
    gray: 16-bit
  Channel statistics:
    Pixels: 307200
    Gray:
      min: 0 (0)   <---- note range
      max: 255 (1)   <---- note range
      mean: 11.5124 (0.0451469)
      standard deviation: 41.0785 (0.161092)
      kurtosis: 16.6724
      skewness: 4.09705
      entropy: 0.177784

Code: Select all

im6hdri identify -verbose tmpB6.mpcImage: tmpB6.mpc
  Format: MPC (Magick Persistent Cache image format)
  Class: DirectClass
  Geometry: 640x480+0+0
  Units: Undefined
  Type: Grayscale
  Endianess: Undefined
  Colorspace: Gray
  Depth: 8/16-bit
  Channel depth:
    gray: 16-bit
  Channel statistics:
    Pixels: 307200
    Gray:
      min: 191.253 (0.750011)   <---- note range
      max: 211.725 (0.830293)   <---- note range
      mean: 194.104 (0.761191)
      standard deviation: 4.05394 (0.0158978)
      kurtosis: 2.70002
      skewness: 1.70747
      entropy: 0.676202

IM7 HDRI

Code: Select all

im7 magick logo: \
-define convolve:scale=50%! -bias 50% \
\( -clone 0 -morphology Convolve Sobel:0  \) \
\( -clone 0 -morphology Convolve Sobel:90  \) \
-delete 0 -solarize 50%  -level 50,0%  \
-compose Lighten -composite \
-separate -evaluate-sequence Max \
-auto-level +write tmpA7.mpc \
-blur 0x20 tmpB7.mpc

Code: Select all

im7 magick identify -verbose tmpA7.mpcImage: tmpA7.mpc
  Format: MPC (Magick Persistent Cache image format)
  Class: DirectClass
  Geometry: 640x480+0+0
  Units: Undefined
  Type: Grayscale
  Base type: TrueColor
  Endianess: Undefined
  Colorspace: Gray
  Depth: 8/16-bit
  Channel depth:
    Gray: 16-bit
  Channel statistics:
    Pixels: 307200
    Gray:
      min: 0 (0)   <---- note range same as IM 6
      max: 255 (1)   <---- note range same as IM6
      mean: 11.5124 (0.0451469)
      standard deviation: 41.0785 (0.161092)
      kurtosis: 16.6724
      skewness: 4.09705
      entropy: 0.177784

Code: Select all

im7 magick identify -verbose tmpB7.mpc
Image: tmpB7.mpc
  Format: MPC (Magick Persistent Cache image format)
  Class: DirectClass
  Geometry: 640x480+0+0
  Units: Undefined
  Type: Grayscale
  Base type: TrueColor
  Endianess: Undefined
  Colorspace: Gray
  Depth: 8/16-bit
  Channel depth:
    Gray: 16-bit
  Channel statistics:
    Pixels: 307200
    Gray:
      min: 382.506 (1.50002)   <---- note range different from IM 6
      max: 423.449 (1.66059)   <---- note range different from IM 6
      mean: 388.207 (1.52238)
      standard deviation: 8.10787 (0.0317956)
      kurtosis: 2.70002
      skewness: 1.70747
      entropy: nan

[magick]

Thanks for the problem report. We can reproduce it and will have a patch to fix it in GIT master branch @ https://github.com/ImageMagick/ImageMagick later today. The patch will be available in the beta releases of ImageMagick @ http://www.imagemagick.org/download/beta/ by sometime tomorrow.