Count color pages of TIFF image

[lindsten]

Hi everyone,

I've just started to look at ImageMagick (or actually Magick++) so I apologize for any stupid questions...


I have a multipage TIFF image and need to count how many of the pages are colored and how many are grayscale (from a C++ program). My first thought was to get the number of total pages (don't know how yet) and then retrieve each page using the read("myfile.tiff[n]") syntax. For each page retrieved I call getConstPixels() and then iterate over all the pixels and compare the R, G and B values for each pixel with opacity != TransparentOpacity. If they're not equal the page contains color and I move on to the next page.

Is this the way to go or is there a better (talking performance) approach?


Btw, how do I get the total number of pages? I know how to do it from the command line (identify -format %n myfile.tiff), but what is the C++ equivalent?

/ Mikael

[magick]

To get the number of images with Magick++ use a list which can return its length. To get you started:

• list<Image> imageList;
  readImages( &imageList, "image.tiff" );

To determine of the image is grayscale you could use statistics() and compare the red, green, and blue channels. If they are equal, the image is gray.

[lindsten]

A list seems like a good start And I'll take a look at the statistics function you mention...

Thanks!


But first I have to get Magick++ working (viewtopic.php?f=1&t=12240)!

/ Mikael

[lindsten]

Can't seem to find any statistics function... where should I look?

[magick]

See http://www.imagemagick.org/Magick++/Image.html and look for the statistics() method description:

• statistics
  ImageStatistics *statistics
  Obtain image statistics. Statistics are normalized to the range of 0.0 to 1.0 and are output to the specified ImageStatistics structure. The structure includes members maximum, minimum, mean, standard_deviation, and variance for each of these channels: red, green, blue, opacity (e.g. statistics->red.maximum).

[lindsten]

That's wierd!

I just had that very same page open and I did a search for statistics (several times actually) without hits. I opened your link in another tab and compared the two. In the first tab the statistics function was actually missing ...until I reloaded the page, then it appeared.

Is my browser playing a joke on me, or did you just update the page?


Anyway, thanks for the help!


/ Mikael

[palpacino]

Hi Guys,

For what it is worth, I just found a way to get TIF page count by using the Shell.Application object (in VB and WinXP in my case)...

Code: Select all

    Dim aryArray() As String
    Dim objShell
    Dim objFolder
    Dim strPC As String
    Dim strDM As String
    Dim objFileName
    Dim strRowSource As String
    
    Set objShell = CreateObject("Shell.Application")
    Set objFolder = objShell.NameSpace("C:\FOLDER\")

    For Each objFileName In objFolder.Items
        strDM = objFolder.GetDetailsOf(objFileName, 3)
        strPC = objFolder.GetDetailsOf(objFileName, 13)
        strRowSource = Chr(34) & Format(CDate(strDM), "MM/DD/YY HH:mm AM/PM") & Chr(34) & ";" & Chr(34) & strPC & Chr(34) & ";" & strRowSource
    Next

There are actually 33 Details. They are the same ones you see in windows explorer when you right-click on the columns and select what columns you want to view. In my case, I just got the "Pages" one which is 13 and the date created which is 3.

Other info:

• 0 Name
  1 Size
  2 Type
  3 Date Modified
  4 Date Created
  5 Date Accessed
  6 Attributes
  7 Status
  8 Owner
  9 Author
  10 Title
  11 Subject
  12 Category
  13 Pages
  14 Comments
  15 Copyright
  16 Artist
  17 Album Title
  18 Year
  19 Track Number
  20 Genre
  21 Duration
  22 Bit Rate
  23 Protected
  24 Camera Model
  25 Date Picture Taken
  26 Dimensions
  27 ?
  28 ?
  29 Episode Name
  30 Program Description
  31 ?
  32 Audio sample size
  33 Audio sample rate

[jaffamuffin]

removed/ mistakes...