Image Comparision on percentage format

Question

I want to know whether it's possible to comapre images using asp.net irrespective of their format,size and result should be in percenatge format like 80%-90% like that...

Iam comparing two similar images taken from a webcam but when i compared it pixel by pixel ,there is difference in pixels so my program showing those are two DIFFERENT IMAGES

SO I WANT TO GET THE RESULT IN PERCENTAGE FORMAT PLESE HELP ME ON THIS

Ben · Answer

one function resizes the second image to match the first one one function returns the difference between the colors of two pixels as a percentage. I think that could work. Didn't do much testing on it though. public Double Compare(Image img1_ Image img2_) { //total number of pixels int pixelNb = img1_.Width * img1_.Height; Double percent = 100; Bitmap resized_img2_ = ResizeBitmap((Bitmap)img2_ img1_.Width img1_.Height); for (int i = 0; i { for (int j = 0; i { percent -= ColorCompare(((Bitmap)img1_).GetPixel(i j) ((Bitmap)resized_img2_).GetPixel(i j))/pixelNb; } } return percent; } public Bitmap ResizeBitmap(Bitmap b int nWidth int nHeight) { Bitmap result = new Bitmap(nWidth nHeight); using (Graphics g = Graphics.FromImage((Image)result)) g.DrawImage(b 0 0 nWidth nHeight); return result; } public Double ColorCompare(Color c1 Color c2) { return Double.Parse((Math.Abs(c1.B - c2.B) + Math.Abs(c1.R - c2.R) + Math.Abs(c1.G - c2.G)).ToString())*100 / (3*255); }

Pramod Kumar Nandagiri · Answer

yes Mr Ben I got that(i instead of j) and u r code helped me a lot thanku very much

Ben · Answer

I type a j instead of an i. Works better now. Tested the function with a few images while looking for the bug and the values it returns seems reliable alright. Let me know if you have other problems with this. Edit : One more thing the resizing of the image can cause the loss of some pixels in the process so you won't get 100% if you compare the same image with two different sizes but it stays around 95-100 %. Depending on what you will use this function for and the kind of image you should do some testing and find out what percentage is OK for you. public Double Compare(Image img1_ Image img2_) { //total number of pixels int pixelNb = img1_.Width * img1_.Height; Double percent = 100; Bitmap resized_img2_ = ResizeBitmap((Bitmap)img2_ img1_.Width img1_.Height); for (int i = 0; i { for (int j = 0; j { percent -= ColorCompare(((Bitmap)img1_).GetPixel(i j) ((Bitmap)resized_img2_).GetPixel(i j))/pixelNb; } } return percent; } public Bitmap ResizeBitmap(Bitmap b int nWidth int nHeight) { Bitmap result = new Bitmap(nWidth nHeight); using (Graphics g = Graphics.FromImage((Image)result)) g.DrawImage(b 0 0 nWidth nHeight); return result; } public Double ColorCompare(Color c1 Color c2) { return Double.Parse((Math.Abs(c1.B - c2.B) + Math.Abs(c1.R - c2.R) + Math.Abs(c1.G - c2.G)).ToString())*100 / (3*255); }

Pramod Kumar Nandagiri · Answer

Hi ben i tested the code which u sent it is giving the Argument out of range exception with the following errorI an trying to solve it please tellme if u have any idea about this error Parameter must be positive and Parameter name: y

Pramod Kumar Nandagiri · Answer

Hi Roei Bar i have already seen the webpage which u sent any way thax verymuch but what i want is i take photos of a tube light when it is on and off if i compare the photos that both photos with light is on the risult should be IMAGES ARE SAME IF I COMPARE the photos like one photo with light is on and another with light is off Then result should be IMAGES ARE DIFFERENT This we won't get with image.getpixel(); method when we compare like this the result is always IMAGES ARE DIFFRENT  IT gives putput IMAGES ARE SAME only the same photo is compared with it self with diff name So to get our required type of output i think the process is different from pixel comparision it may be comparing the colors in the image or comparing RGB value I NEED HELP ON THIS TYPE OF COMPARISON OF IMAGES IT SHOULD RESULT IMAGES ARE SAME when both photos consists light is on and those photos are taken at different time

Roei Bar · Answer

i think this should help http://www.codeproject.com/KB/GDI-plus/comparingimages.aspx