resources/images: Fix TestColorLuminance on s390x

htesting/hqt/checkers.go

@@ -16,6 +16,7 @@ package hqt
 import (
 	"errors"
 	"fmt"
+	"math"
 	"reflect"
 	"strings"
 
@@ -38,6 +39,11 @@ var IsSameType qt.Checker = &typeChecker{
 	argNames: []string{"got", "want"},
 }
 
+// IsSameFloat64 asserts that two float64 values are equal within a small delta.
+var IsSameFloat64 = qt.CmpEquals(cmp.Comparer(func(a, b float64) bool {
+	return math.Abs(a-b) < 0.0001
+}))
+
 type argNames []string
 
 func (a argNames) ArgNames() []string {