Histogram: Perbedaan antara revisi

Pada statistik, '''histogram''' adalah tampilan grafis dari tabulasi frekuensi yang digambarkan dengan grafis batangan sebagai manifestasi ''[[data binning]]''. Tiap tampilan batang menunjukkan proporsi [[frekuensi]] pada masing-masingsetiap deret kategori yang berdampingan ([[bahasa inggris|en]]: ''adjacent'') dengan interval yang tidak tumpang tindih ([[bahasa inggris|en]]: ''non-overlapping'').<ref>Howitt, D. and Cramer, D. (2008) "Statistics in Psychology". Prentice Hall</ref>

''Nilai gamma'' merupakan kuantifikasi kontras pada fotografi didefinisikan secara matematis:

dimana <math>V_{out}</math> dan <math>V_{in}</math> adalah relasi bolak balik ([[bahasa inggris|en]]:''reversal'') antara reaksi substrat perak nitrat pada negatif film dan [[iluminasi]] yang mengenainya. Relasi ini dipetakan menjadi diagram yang disebut '''''characteristic curves''''',<ref>{{cite web | url = http://www.kodak.com/global/en/professional/support/techPubs/f4017/f4017.jhtml | title = KODAK PROFESSIONAL TRI-X 400 Film / 400TX | 3 = Kokak Professional Support | access-date = 2009-09-12 | archive-date = 2009-08-02 | archive-url = https://web.archive.org/web/20090802104632/http://www.kodak.com/global/en/professional/support/techPubs/f4017/f4017.jhtml | dead-url = yes }}</ref> '''Hurter–Driffield curves''',<ref name=palmer/> '''H–D curves''',<ref name=palmer>{{cite book|title = Advanced University Physics|author = Stuart B. Palmer and Mircea S. Rogalski|publisher = Taylor & Francis|year = 1996|isbn = 2884490655|url = http://books.google.com/books?id=TF6Igz5lJLgC&pg=PA349&dq=hurter-driffield-curve+h-d-curve&lr=&as_brr=3&ei=songR5KAJIWusgOWlPQU&sig=FgC6_uAklssPUpNaUyyr2lS0hNk }}</ref> '''HD curves''',<ref>{{cite book|title = Multielement Detection Systems for Spectrochemical Analysis|author = Kenneth W. Busch and Marianna A. Busch|publisher = Wiley-Interscience|year = 1990|isbn = 0471819743|url = http://books.google.com/books?id=9H0W1J-Rku4C&pg=PA339&dq=h-d-curve+density&lr=&as_brr=3&ei=qYzgR46lBYbosQOrzpgV&sig=_kTikTsCw2-7B8XvfO6y73rmTkc#PPA341,M1 }}</ref> '''H & D curves''',<ref>{{cite book|title = Principles of Radiographic Imaging: An Art and a Science|author = Richard R. Carlton, Arlene McKenna Adler|publisher = Thomson Delmar Learning|year = 2000|isbn = 0766813002|url = http://books.google.com/books?id=oA-eBHsapX8C&pg=PA318&dq=h%26d-curve+density&lr=&as_brr=3&ei=to3gR5GCLI6eswOs98kV&sig=s_vE4f5PMysrrCtgM7_HJrsRu_Y }}</ref> '''D–logE curves''',<ref>{{cite book|title = Remote Sensing Geology|author = Ravi P. Gupta|publisher = Springer|year = 2003|isbn = 3540431853|url = http://books.google.com/books?id=74T8X1zqgF4C&pg=PA62&dq=d-log-e-curve+density&lr=&as_brr=3&ei=eY7gR4qWEILusgO60YCrAg&sig=MBImrU6KwlZwoV29Xl1PywwEINQ }}</ref> or '''D–logH curves'''.<ref>{{cite book|title = The Focal Encyclopedia of Photography|author = Leslie D. Stroebel and Richard D. Zakia|publisher = Focal Press|year = 1993|isbn = 0240514173|url = http://books.google.com/books?id=CU7-2ZLGFpYC&pg=PA794&dq=d-log-h-curve+density&lr=&as_brr=3&ei=BI_gR6qIGIiUtgOY5tEV&sig=wfoH3l-C-AKifDLLObbnYn7FrHg }}</ref>

sehingga variabel <math>\gamma</math> disebut '''''gamma correction''''' atau '''''gamma nonlinearity'''''.<ref>{{cite book|title = Digital Video and HDTV: Algorithms and Interfaces|author = Charles A. Poynton|publisher = Morgan Kaufmann|year = 2003|isbn = 1558607927|url = http://books.google.com/books?id=ra1lcAwgvq4C&pg=RA1-PA630&dq=gamma-encoding&lr=&as_brr=3&ei=WHfDR6q4J4OmswOGiZXPDw&sig=OYiWf7BJ2ACTek1UAsbcXOIlvP0 }}</ref> Pada saat <math>\gamma > 1</math> sering disebut '''''expansion gamma''''' atau '''''decoding gamma'''''. Sebaliknya pada saat <math>\gamma < 1</math> sering disebut '''''compressed gamma''''' atau '''''encoding gamma'''''.