Question

I am looking for a very quick way to render dynamic images from small tiles placed on some background (imagine dynamically rendering a chess game and sending images after each player makes a move).
So the procedure seems to be quite simple:
1. Take some background
2. Put transparent images of chess figures from top to bottom using image offsets (to have correct perspective)
3. Save the whole picture as gif

Tried using imagemagick:

using something similar to:

convert -page 176x220 -gravity SouthWest 1.png   -page +35+30 -gravity SouthWest 1.png     -page +62+50       1.png   -page +10+55 1.png -background none  -compose DstOver  -flatten      result.gif

And graphics magick in similar way:
gm convert … -page+35+-30 -flatten..

But was not impressed, GraphicsMagick provided better results but:

SERVER:

             user     system      total        real
all:     0.000000   0.000000  47.650000 ( 70.991829)
small:   0.000000   0.000000   6.600000 (  8.110900)
medium:  0.000000   0.000000   6.820000 (  8.494131)
large:   0.000000   0.000000  10.890000 ( 15.818351)
extreme:  0.000000   0.000000  11.160000 ( 19.873541)
biggest:  0.000000   0.000000  11.640000 ( 14.327450)

On local Phenom II x6:

             user     system      total        real
all:     0.000000   0.000000   1.980000 (  0.757320)
small:   0.000000   0.000000   0.330000 (  0.082142)
medium:  0.000000   0.000000   0.380000 (  0.127744)
large:   0.000000   0.000000   0.410000 (  0.147252)
extreme:  0.000000   0.000000   0.440000 (  0.180338)
biggest:  0.000000   0.000000   0.470000 (  0.210802)

Thought maybe the file loading is the issue, tried Rmagick(script from: http://www.imagemagick.org/RMagick/doc/ilist.html#mosaic ):

    require "benchmark"
    require 'RMagick'

    #Demonstrate the mosaic method

    a = Magick::ImageList.new

    26.times do
      a.read("csii/some_asset.miff")
    end


    b = Magick::ImageList.new
    page = Magick::Rectangle.new(0,0,0,0)
    a.scene = 0
    2.times do |i|
        2.times do |j|
            b << a.scale(1)
            page.x = j * b.columns
            page.y = i * b.rows
            b.page = page
            (a.scene += 1) rescue a.scene = 0
        end
    end

    # Make a 5x5 mosaic
    #mosaic = b.flatten_images
    #mosaic.write("mosaic.gif")

    # mosaic.display
    Benchmark.bm(7) do |ben|
      ben.report("tiny:")   {mosaic = b.mosaic}
    end

    exit

The result is even more wierd:
THIS IS FOR A TINY 2*2 tiles image

SERVER:

         user     system      total        real
tiny:   16.210000   0.000000  16.210000 ( 16.982007)

PHENOM:

             user     system      total        real
tiny:    0.000000   0.010000   0.010000 (  0.001637)

ADDITIONAL INFO:

INPUT FILE FORMATS: tried png and miff

OUTPUT: must be gif

SERVER: 1 XEON core on VPS ~2.2Ghz

PHENOM: 6* 3.2Ghz

Version differences:

Phenom
Version: ImageMagick 6.5.7-8 2010-12-02 Q16 http://www.imagemagick.org

Server 
Version: ImageMagick 6.5.1-0 2010-12-02 Q16 OpenMP http://www.imagemagick.org

QUESTIONS

1. Any ideas for the up to 10000 times reduction in speed?
2. Any ideas of how I could achieve this task in any other way(other GM or IM function?) or method (Trying out chunky_PNG now (with oily_png ext.)?
3. The old 2d games of DOS era could render even more pixels at 60fps, so I guess it should be able to accomplish this on a 2Ghz CPU (200ms would be OK I guess)?

Answer 1

It seems every time I ask a question on SO, the answer comes to me immediately.

This time it seems the performance issue is because of OpenVz VPS and OpenMP in IM and GM. After recompiling without OpenMP feature, the performance is great on the server.