%Matlab版HOG代碼
function?F?=?hogcalculator（img?cellpw?cellph?nblockw?nblockh...
????nthet?overlapissigned?normmethod）;

%?HOG特征由Dalal在2005?cvpr?的一篇論文中提出

%?NORMMETHOD：重疊塊中的特征標準化函數(shù)的方法
%???????e為一個設(shè)定的很小的數(shù)使分母不為0
%???????v為標準化前的特征向量
%???????‘none‘?which?means?non-normalization;
%???????‘l1‘?which?means?L1-norm?normalization;?V=V/（V+e）
%???????‘l2‘?which?means?L2-norm?normalization;?V=V/根號（V平方+e平方）
%???????‘l1sqrt‘V=根號（V/（V+e））
%???????‘l2hys‘l2的省略形式。將V最大值限制為0.2

if?nargin?????%?在DALAL論文中指出的在rows:128*columns:64情況下的最佳值，設(shè)定為DEFAULT
????cellpw?=?8;
????cellph?=?8;
????nblockw?=?2;
????nblockh?=?2;
????nthet?=?9;
????overlap?=?0.5;
????issigned?=?‘unsigned‘;
????normmethod?=?‘l2hys‘;
else
????if?nargin?????????error（‘輸入?yún)?shù)不足.‘）;
????end
end

[M?N?K]?=?size（img）;??%M為行數(shù)，N為列數(shù)，K為維數(shù)
if?mod（Mcellph*nblockh）?~=?0???%行數(shù)必須為塊的高度的整數(shù)倍
????error（‘圖片行數(shù)必須為塊的高度的整數(shù)倍.‘）;
end
if?mod（Ncellpw*nblockw）?~=?0???%列數(shù)必須為塊的寬度的整數(shù)倍
????error（‘圖片列數(shù)必須為塊的寬度的整數(shù)倍.‘）;
end?????????????????????????????
if?mod（（1-overlap）*cellpw*nblockw?cellpw）?~=?0?||...??%要使滑步后左邊是整數(shù)
????????mod（（1-overlap）*cellph*nblockh?cellph）?~=?0
????error（‘滑步的像素個數(shù)必須為細胞單元尺寸的整數(shù)倍‘）;
end

%設(shè)置高斯空間權(quán)值窗口的方差
delta?=?cellpw*nblockw?*?0.5;


%計算梯度矩陣??梯度的計算【-1，0，1】效果是很好的，而3*3的sobel算子或者2*2的對角矩陣反而會系統(tǒng)的降低效果
hx?=?[-101];
hy?=?-hx‘;???%轉(zhuǎn)置
gradscalx?=?imfilter（double（img）hx）;??%imfilter是濾波器，hx表示濾波掩膜
gradscaly?=?imfilter（double（img）hy）;

if?K?>?1
????gradscalx?=?max（max（gradscalx（::1）gradscalx（::2））?gradscalx（::3））;??%取RGB中最大值
????gradscaly?=?max（max（gradscaly（::1）gradscaly（::2））?gradscaly（::3））;
end
gradscal?=?sqrt（double（gradscalx.*gradscalx?+?gradscaly.*gradscaly））;??%梯度矩陣?gradscal

%?計算梯度方向矩陣
gradscalxplus?=?gradscalx+ones（size（gradscalx））*0.0001;??%防止為0，所以gradscalx加了0.0001
gradorient?=?zeros（MN）;?????????????????????????????????%初始化梯度方向矩陣
%?unsigned?situation:?orientation?region?is?0?to?pi.
if?strcmp（issigned?‘unsigned‘）?==?1?????????????????????%無向的情況
????gradorient?=...
????????atan（gradscaly./gradscalxplus）?+?pi/2;???????????%加pi/2因為atan的區(qū)間取值從-pi/2開始
????or?=?1;
else
????%?signed?situation:?orientation?region?is?0?to?2*pi.?%有向的情況
????if?strcmp（issigned?‘signed‘）?==?1
????????idx?=?find（gradscalx?>=?0?&?gradscaly?>=?0）;
????????gradorient（idx）?=?atan（gradscaly（idx）./gradscalxplus（idx））;
????????idx?=?find（gradscalx?????????gradorient（idx）?=?atan（gradscaly（idx）./gradscalxplus（idx））?+?pi;
????????idx?=?find（gradscalx?>=?0?&?gradscaly?????????gradorient（idx）?=?atan（gradscaly（idx）./gradscalxplus（idx））?+?2*pi;
????????or?=?2;
????else
?????%??error（‘Incorrect?ISSIGNED?parameter.‘）;
????????error（‘參數(shù)ISSIGNED輸入有誤‘）;
????end
end

%?計算塊的滑步
xbstride?=?cellpw*nblockw*（1-overlap）;???%x方向的滑步
ybstride?=?cellph*nblockh*（1-overlap）;
xbstridend?=?N?-?cellpw*nblockw?+?1;?????%x方向塊左角能達到的最大值
ybstridend?=?M?-?cellph*nblockh?+?1;

%?塊總數(shù)=ntotalbh*ntotalbw
ntotalbh?=?（（M-cellph*nblockh）/ybstride）+1;?%除了第一個，后面每

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件??????42770??2011-10-30?21:59??pedestrain\alpha.mat

?????文件????????173??2011-10-30?21:59??pedestrain\bias.mat

?????文件???????9572??2011-05-11?18:32??pedestrain\HOG.m

?????文件???????3809??2013-01-18?11:51??pedestrain\main.asv

?????文件???????3811??2011-10-21?15:40??pedestrain\main.m

?????文件????????290??2011-05-14?15:28??pedestrain\myplot.m

?????文件????????211??2011-11-04?16:42??pedestrain\narrowarray.mat

?????文件???????1072??2013-01-17?20:31??pedestrain\newSVM.asv

?????文件???????1072??2011-10-30?22:46??pedestrain\newSVM.m

?????文件????????176??2011-10-30?21:59??pedestrain\nsv.mat

?????文件?????234689??2011-05-12?14:43??pedestrain\people0.png

?????文件?????234689??2011-05-12?14:43??pedestrain\postive\people0.png

?????文件?????234689??2011-05-12?14:43??pedestrain\postive\people0_2.png

?????文件?????234689??2011-05-12?14:43??pedestrain\postive\people0_3.png

?????文件?????234689??2011-05-12?14:43??pedestrain\postive\people0_4.png

?????文件???????1556??2011-05-15?15:42??pedestrain\readimg2.m

?????文件????????965??2011-10-28?21:50??pedestrain\readneg.m

?????文件????????983??2013-01-18?11:51??pedestrain\readpos.asv

?????文件????????984??2011-10-28?20:37??pedestrain\readpos.m

?????文件????1279012??2013-01-17?17:25??pedestrain\testvector.mat

?????文件????????815??2013-01-17?22:51??pedestrain\TSVM.asv

?????文件????????803??2013-01-17?22:54??pedestrain\TSVM.m

?????目錄??????????0??2013-01-24?17:20??pedestrain\postive

?????目錄??????????0??2013-01-18?10:28??pedestrain

-----------?---------??----------?-----??----

??????????????2521519????????????????????24