Image Histogram

MaurizioIEC

Hi Yuri,
thank you very much.
In the meantime I found this solution that is a little bit different from yours, let me know if it is correct.

    Dim hist As MediaCy.IQL.Operations.McHistogram = ImEmpty.Histogram
    Dim dMedia As Double = hist.Mean(0)
    Dim dMinimo As Double = hist.Min(0)
    Dim dMassimo As Double  = hist.Max(0)
    Dim dStdDev As Double = hist.StdDev(0)
The image is 8GL but, in case of RGB24, using the index (0) Red (1) Green and (2) Blu I got all the info
I would like to get the histo Moda (max frequency index ) too.
I tried to use the followed code it reports me an error (HRESULT 0x80020011 DISP_E_NOTACOLLECTION)
Dim dMode As Double = hist.Mode(0) 
Probabily it is not the parameter I need.
Ciao
Maurizio

YuriG

Hi Maurizio,

hist.Mode is not what you want, it's just a mode to calculate histogram:
Mode - A read-write property used to specify how the histogram values and statistics are computed and reported. (see Public Enumeration mcHistogramMode).

The statistical Mode parameter can be extracted using another method, find bin value with maximum amplitude:

    Public Sub HistMode
        Dim histogram As MediaCy.IQL.Operations.McHistogram=ThisApplication.ActiveImage.Histogram
        Dim Channel As Integer=0'check Red channel
        'find mode: find bin value with maximum amplitude
        Dim maxVal As Long = -1
        Dim modeBin As Long = -1
        For bin As Long = 0 To histogram.BinCount - 1
            Dim binVal As Long = histogram.Values(bin, Channel)
            If binVal > maxVal Then
                maxVal = binVal
                modeBin = bin
            End If
        Next
        If modeBin >= 0 Then
            Debug.Print "Histogram mode value  = " & histogram.BinXValues(modeBin)
        End If
    End Sub

Yuri

MaurizioIEC

thank you Yuri, I did the same.
Ciao
Maurizio