how to speed up text annotation to tiff files

[eltato]

Hello.

I'm trying to put some text on a tiff file and it takes around 5-6 seconds. Is there a way to speed up the process?
I execute the next command:

Code: Select all

convert aaa.tif -font Arial -pointsize 100 -gravity West -draw "text 0,0 'hola'" -monitor -compress Group4 -define quantum:polarity=min-is-white stamp.tif

I use the -monitor swith so I can see that it takes more time in Dither image colors: process. Is there anyway of disable dithering? I've tried +dither but it takes the same time.

The input tiff file is like this:

Code: Select all

/opt/imagemagick/bin/identify -verbose aaa.tif
Image: aaa.tif
  Format: TIFF (Tagged Image File Format)
  Class: DirectClass
  Geometry: 2479x3508+0+0
  Resolution: 300x300
  Print size: 8.26333x11.6933
  Units: PixelsPerInch
  Type: Bilevel
  Base type: Bilevel
  Endianess: LSB
  Colorspace: RGB
  Depth: 1-bit
  Channel depth:
    gray: 1-bit
  Channel statistics:
    gray:
      min: 0 (0)
      max: 1 (1)
      mean: 0.763653 (0.763653)
      standard deviation: 0.424837 (0.424837)
      kurtosis: -0.45943
      skewness: -1.2412
  Histogram:
   6640984: (255,255,255) #FFFFFF white
   2055348: (  0,  0,  0) #000000 black
  Rendering intent: Undefined
  Interlace: None
  Background color: white
  Border color: rgb(223,223,223)
  Matte color: grey74
  Transparent color: black
  Page geometry: 2479x3508+0+0
  Dispose: Undefined
  Iterations: 0
  Compression: Group4
  Orientation: TopLeft
  Properties:
    create-date: 2009-04-08T16:55:47+02:00
    modify-date: 2009-04-08T16:55:47+02:00
    signature: 3d9f8b09ba3d3deb80b5d89ed0960e89474030b7c22fba854ea9428ce29f1a03
    tiff:document: 0000000001.tif
    tiff:rows-per-strip: 3508
    tiff:software: ImageMagick 6.5.1-0 2009-04-06 Q16 http://www.imagemagick.org
    tiff:timestamp: 2009:01:21 10:56:40
  Artifacts:
    verbose: true
  Tainted: False
  Filesize: 509kb
  Number pixels: 8.293mb
  Version: ImageMagick 6.5.1-0 2009-04-06 Q16 http://www.imagemagick.org

I've compiled ImageMagick 6.5.1-0 version.


Thanks in advance.

[eltato]

Anybody?

[magick]

ImageMagick is not optimized for processing 1-bit images. Text annotation adds shading to your image so it must be color reduced afterwards to recreate a monochome image. Color reduction is rather slow in ImageMagick. You can try thresholding which is quite fast but it may not return the results you are looking for.

[anthony]

ordered dithing is also faster than the normal color reduction processing.

[eltato]

Hi and thank you very much for your answers.
Adding the option -threshold 50% the process is much faster.
Without thresholding:

Code: Select all

time /opt/imagemagick/bin/convert aaa.tif -font Arial -pointsize 100 -gravity West -draw "text 0,0 'hola'" -compress Group4 -define quantum:polarity=min-is-white stamp.tif

real    0m5.506s
user    0m4.944s
sys     0m0.552s

With thresholding:

Code: Select all

time /opt/imagemagick/bin/convert aaa.tif -font Arial -pointsize 100 -gravity West -draw "text 0,0 'hola'" -compress Group4 -define quantum:polarity=min-is-white -threshold 50% stamp.tif

real    0m0.579s
user    0m0.224s
sys     0m0.348s

Almost ten times faster.
The result image is quite good and is enough for me at the moment.