5. GOODWILL AND INTANGIBLE ASSETS

The changes in the carrying amount of goodwill by segment for fiscal 2018 and 2019 are as follows (in thousands):


					Optoelectronics
					and
	Security		Healthcare		Manufacturing
	Division		Division		Division		Consolidated
Balance as of June 30, 2017	$	155,083	$	40,129	$	46,917	$	242,129
Goodwill acquired or adjusted during the period		36,889		—		13,986		50,875
Foreign currency translation adjustment		(162)		28		(657)		(791)
Balance as of June 30, 2018	$	191,810	$	40,157	$	60,246	$	292,213
Goodwill acquired or adjusted during the period		8,340		—		7,019		15,359
Foreign currency translation adjustment		(71)		(93)		(300)		(464)
Balance as of June 30, 2019	$	200,079	$	40,064	$	66,965	$	307,108

The measurement periods for the valuation of assets and liabilities acquired may extend up to one year. Adjustments in purchase price allocations may require a change in the amounts allocated to goodwill during the periods in which the adjustments are determined.

Intangible assets subject to amortization consisted of the following (amounts in thousands):


		June 30, 2018						June 30, 2019
	Weighted	Gross						Gross
	Average	Carrying		Accumulated		Intangibles		Carrying		Accumulated		Intangibles
	Lives	Value		Amortization		Net		Value		Amortization		Net
Amortizable assets:
Software development costs	9 years	$	28,174	$	(9,423)	$	18,751	$	29,393	$	(12,747)	$	16,646
Patents	19 years		8,401		(1,618)		6,783		8,688		(1,927)		6,761
Developed technology	10 years		52,780		(9,706)		43,074		53,460		(14,050)		39,410
Customer relationships/backlog	7 years		63,398		(17,891)		45,507		63,101		(22,132)		40,969
Total amortizable assets			152,753		(38,638)		114,115		154,642		(50,856)		103,786
Non-amortizable assets:
IPR&D			2,290		—		2,290		2,290		—		2,290
Trademarks			25,596		—		25,596		26,878		—		26,878
Total intangible assets		$	180,639	$	(38,638)	$	142,001	$	183,810	$	(50,856)	$	132,954

During fiscal 2018 , we recorded impairment charges related to intangible assets of $2.5 million due to changes in facts and circumstances associated with the shift in strategic direction which led us to conclude that the carrying value of the intangible assets was not recoverable. These intangible assets impairment charges were included in impairment, restructuring and other charges in our consolidated statement of operations.

Amortization expense for fiscal 2017, 2018 and 2019 was $12.3 million, $19.5 million and $21.4 million, respectively. Future acquisitions could cause these amounts to increase. At June 30, 2019, the estimated future amortization expense was as follows (in thousands):


2020	$	19,960
2021		18,825
2022		14,984
2023		13,904
2024		12,883
Thereafter, including assets that have not yet begun to be amortized		23,230
Total	$	103,786

Software development costs for software products incurred before establishing technological feasibility are charged to operations. Software development costs incurred after establishing technological feasibility are capitalized on a product by product basis until the product is available for general release to customers at which time amortization begins. Annual amortization, charged to cost of goods sold, is the amount computed using the ratio that current revenues for a product bear to the total current and anticipated future revenues for that product. In the event that future revenues are not estimable, such costs are amortized on a straight-line basis over the remaining estimated economic life of the product. Amortizable assets that have not yet begun to be amortized are included in Thereafter in the table above. During fiscal 2017, 2018 and 2019, we capitalized software development costs in the amounts of $2.3 million, $1.8 million and $2.7 million, respectively.