color information

Question

User2045693258 posted

ok, here's what i wanna do

 loop through a folder of images and compare the dominant color in each image against a range of hex codes so if a jpeg has 50 blue pixels, 25 black pixels and 25 red pixels i know it's predominantly blue

is something like this possible, anyone know where i should start?

Answer 1

User815882678 posted

I would begin by searching through the System.Drawing namespace at:

http://msdn.microsoft.com/en-us/library/system.drawing.graphics.aspx

Also, take a look at:

http://www.bobpowell.net/lockingbits.htm

 

 

 

Answer 2

User2045693258 posted

 ok, after much digging and reading (i'm admittely not very good at this programming thing, data access i'm fine at but stuff like this...urgh) i've found the following function but can anybody help me convert it into something that would run on a web page as picturebox is a windows forms control....please somebody help as this is driving me crazy

 

Function AverageRGB(ByRef P As PictureBox) As Long

        Dim Count As Long
        Dim Red As Long
        Dim Green As Long
        Dim Blue As Long
        Dim Hexed As String
        Dim X As Long
        Dim Y As Long
        Count = 0


        For X = 0 To P.Width Step P.Width \ 32


            For Y = 0 To P.Height Step P.Height \ 32
                Hexed = Right("00000" & Hex(P.Point(X, Y)), 6)
                Red = Red + CLng("&h" & Right(Hexed, 2))
                Green = Green + CLng("&h" & Mid(Hexed, 3, 2))
                Blue = Blue + CLng("&h" & Left(Hexed, 2))
                Count = Count + 1
            Next

        Next

        AverageRGB = RGB(Red \ Count, Green \ Count, Blue \ Count)

    End Function

Answer 3

User815882678 posted

Have you looked into System.Drawing.Image?

Answer 4

User2045693258 posted

 i figured it all out in the end using lockbits. if anyone ever needs the code, give me a shout at [e-mail]

Answer 5

User815882678 posted

Would you mind posting some snippets here?

Answer 6

User2045693258 posted

i'll post a link to the complete source here soon. i'm building a dynamic stock library project that gets color information and loads of other stuff including creating thumbnails on the fly etc . it should have a lot of useful gdi+ stuff in it as it's the one area of .net that i like the most :)