// TestMean tests the mean quantizer on png files found in the source
// directory. Output files are prefixed with _mean_. Files begining with
// _ are skipped when scanning for input files. Note nothing is tested
// with a fresh source tree--drop a png or two in the source directory
// before testing to give the test something to work on. Png files in the
// parent directory are similarly used for testing. Put files there
// to compare results of the different quantizers.
func TestMean(t *testing.T) {
for _, p := range glob(t) {
f, err := os.Open(p)
if err != nil {
t.Log(err) // skip files that can't be opened
continue
}
img, err := png.Decode(f)
f.Close()
if err != nil {
t.Log(err) // skip files that can't be decoded
continue
}
pDir, pFile := filepath.Split(p)
for _, n := range []int{16, 256} {
// prefix _ on file name marks this as a result
fq, err := os.Create(fmt.Sprintf("%s_mean_%d_%s", pDir, n, pFile))
if err != nil {
t.Fatal(err) // probably can't create any others
}
var q quant.Quantizer = mean.Quantizer(n)
if err = png.Encode(fq, q.Image(img)); err != nil {
t.Fatal(err) // any problem is probably a problem for all
}
}
}
}
