Коллеги, ну что мы тут мусолим без профайлера
добрый день, запустил профайлер
Type: cpu
Time: Jun 27, 2018 at 12:53pm (MSK)
Duration: 13.05s, Total samples = 4.26s (32.64%)
Entering interactive mode (type "help" for commands, "o" for options)
(pprof) top
Showing nodes accounting for 3530ms, 82.86% of 4260ms total
Dropped 41 nodes (cum <= 21.30ms)
Showing top 10 nodes out of 69
flat flat% sum% cum cum%
960ms 22.54% 22.54% 1040ms 24.41% runtime.mallocgc
500ms 11.74% 34.27% 500ms 11.74% image/color.(*NRGBA).RGBA
390ms 9.15% 43.43% 390ms 9.15% image.(*NRGBA).NRGBAAt
310ms 7.28% 50.70% 1760ms 41.31% image.(*NRGBA).At
280ms 6.57% 57.28% 1420ms 33.33% runtime.convT2Inoptr
260ms 6.10% 63.38% 290ms 6.81% image/png.filter
260ms 6.10% 69.48% 260ms 6.10% runtime.memmove
210ms 4.93% 74.41% 3510ms 82.39% main.MatrixImageGenerator.Generate
180ms 4.23% 78.64% 180ms 4.23% hash/adler32.update
180ms 4.23% 82.86% 630ms 14.79% image/png.(*decoder).readImagePass