[問題] BCB影像處理雜訊
各位板友好
小弟是剛學影像處理的新手
目前在研究雜訊程式碰到了許多問題
雖然有對照書本寫的雜訊公式來看
可是還是不知道以下三段程式是怎麼做加入雜訊運算
首先是Impulse noise的部份
level值算是強度嗎?那麼它有特定範圍嗎?
在這段程式裡有寫到pix = cp*x
cp是定義的色平面,那將它乘以x可以得到什麼?
再者是Gaussian noise
_
書本寫高斯雜訊為p(z)=((1/2^0.5)*標準差)*e^(-(z-z)^2)/2*標準差^2
可是對照下面的程式
一開始定義的mean和sd是什麼?
然後在程式裡的運算
sqrt12和sqrt10是代表什麼?是要再另外定義它成為某個數字還是???
我真的不太清楚這樣的寫法跟書本的公式有什麼關聯性
如果有板友了解的話可以幫我解惑嗎
最後是Uniform Noise的部份
一樣是不清楚公式跟程式的關連性...
雖然說mean和sd是要輸入的值
可是他們主要是代表控制什麼?
然後在迴圈裡的ran到sum3=...應該是在計算p(z)
可是我研究許久還是不懂到底程式是怎麼表達p(z)...
(Impulse Noise)
prob = StrToInt(Form11->Edit1->Text);
level = StrToInt(Form11->Edit2->Text);
randomize();
for (int y = 0;y < nBitmap->Height;y++)
{
aptr = (Byte*)nBitmap->ScanLine[y];
for (int x = 0;x < nBitmap->Width;x++)
if (random(100) <= prob)
{
pix1 = cp * x;
aptr[pix1] = (Byte)(aptr[pix1]+level);
aptr[pix1+1] = (Byte)(aptr[pix1+1]+level);
aptr[pix1+2] = (Byte)(aptr[pix1+2]+level);
}
}
(Gaussian Noise)
mean = StrToInt(Form11->Edit1->Text);
sd = StrToFloat(Form11->Edit2->Text);
//ShowMessage("Mean = "+IntToStr(mean)+",\nSD ="+FloatToStr(sd)+".");
randomize();
for (int y = 0;y < nBitmap->Height;y++)
{
aptr = (Byte*)nBitmap->ScanLine[y];
for (int x = 0;x < nBitmap->Width;x++)
{
total = 0.0;
for (int k = 0;k < 10;k++)
{
ran = (float)(random(100)+1) / 100;
total += (float)sqrt12 * sd * (ran - 0.5);
}
total /= (float)sqrt10;
total += (float)mean;
pix1 = cp * x;
sum1 = total+(float)aptr[pix1];
sum2 = total+(float)aptr[pix1+1];
sum3 = total+(float)aptr[pix1+2];
if (sum1 < 0.0) sum1 = 0.0;
if (sum2 < 0.0) sum2 = 0.0;
if (sum3 < 0.0) sum3 = 0.0;
aptr[pix1] = (Byte)(sum1);
aptr[pix1+1] = (Byte)(sum2);
aptr[pix1+2] = (Byte)(sum3);
}
}
(Uniform Noise)
mean = StrToInt(Form11->Edit1->Text);
sd = StrToFloat(Form11->Edit2->Text);
randomize();
for (int y = 0;y < nBitmap->Height;y++)
{
aptr = (Byte*)nBitmap->ScanLine[y];
for (int x = 0;x < nBitmap->Width;x++)
{
ran = (float)(random(100)+1) / 100;
total = ran - 0.5;
total *= (float)sqrt12;
total *= sd;
total += (float)mean;
pix1 = cp * x;
sum1 = total+(float)aptr[pix1];
sum2 = total+(float)aptr[pix1+1];
sum3 = total+(float)aptr[pix1+2];
if (sum1 < 0.0) sum1 = 0.0;
if (sum2 < 0.0) sum2 = 0.0;
if (sum3 < 0.0) sum3 = 0.0;
aptr[pix1] = (Byte)(sum1);
aptr[pix1+1] = (Byte)(sum2);
aptr[pix1+2] = (Byte)(sum3);
}
}
以上幾個問題煩請板友幫小弟解惑
不好意思一次問太多問題了...
小弟僅能盡量以微薄的P幣答謝回答問題的板友
感謝大家
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 203.74.245.166
推
04/10 23:52, , 1F
04/10 23:52, 1F
→
04/10 23:53, , 2F
04/10 23:53, 2F
→
04/10 23:54, , 3F
04/10 23:54, 3F
→
04/10 23:55, , 4F
04/10 23:55, 4F
→
04/11 00:09, , 5F
04/11 00:09, 5F
推
04/11 00:32, , 6F
04/11 00:32, 6F
推
04/11 00:35, , 7F
04/11 00:35, 7F
→
04/11 00:36, , 8F
04/11 00:36, 8F
→
04/11 00:36, , 9F
04/11 00:36, 9F
→
04/11 00:37, , 10F
04/11 00:37, 10F
→
04/11 00:37, , 11F
04/11 00:37, 11F
→
04/11 00:38, , 12F
04/11 00:38, 12F
→
04/11 00:39, , 13F
04/11 00:39, 13F
→
04/11 00:40, , 14F
04/11 00:40, 14F
→
04/11 00:40, , 15F
04/11 00:40, 15F
→
04/11 00:42, , 16F
04/11 00:42, 16F
推
04/11 00:48, , 17F
04/11 00:48, 17F
→
04/11 00:55, , 18F
04/11 00:55, 18F
→
04/11 02:51, , 19F
04/11 02:51, 19F
推
04/11 10:07, , 20F
04/11 10:07, 20F
→
04/11 10:09, , 21F
04/11 10:09, 21F
→
04/11 10:10, , 22F
04/11 10:10, 22F
→
04/11 10:11, , 23F
04/11 10:11, 23F
→
04/11 10:12, , 24F
04/11 10:12, 24F
討論串 (同標題文章)