Hi Fred/fmw42,
Thanks and apreciate for for answer and help. i have download your maxima script
Let say we work just for search start.png in big.png and replace color to red of start.png ( i dont know it 'll using change color of start.png using imagemagick function or embed/drop another image similart start.png with different color, but i alreay make it start_red.png
Source png fle
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big.png

start.png

start_red.png
Expected Result ( i modify manual using photoshop )
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bigstart_result.png
Step
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1. compare -metric rmse -subimage-search big.png start.png bigstart.png
Result :
bigstart-0.png

bigstart-1.png

2. maxima -r 5 -n 10 -t 50 -d 15 bigstart-1.png
Result :
111,3 gray=64372,250,98.2254%
303,46 gray=59840,233,91.31%
143,86 gray=45002,175,68.6687%
3. How then? to process 3 of result of coordinate and make them as my result like :
bigstart_result.png
Thanks for your help, hope it'll usefull for other people also. Thanks Fred, i'm new comer to this forum