Wednesday, August 5, 2009

Ruby & Excel: Inserting Pictures Into Cells (New and Improved!)

In a previous article, I discussed a method for inserting images into an Excel worksheet. It seems that the Worksheet.Pictures.Insert() method that I demonstrated in that article, though frequently used, is not actually officially documented in the Excel Object Model Reference. An astute reader has called my attention to this fact and, in reply, I hereby present the officially documented---and probably preferred---method for adding an image to a worksheet.

The Worksheet object's Shapes collection includes an AddPicture() method that creates a picture from an existing file and returns a Shape object that represents the new picture. The syntax is:


.AddPicture(Filename, LinkToFile, SaveWithDocument, Left, Top, Width, Height)

All seven arguments are required, but this allows you to specify the position and size of the picture in the method call.

The following code inserts an image into the range of cells from C3 to F5 in the active worksheet:

require 'win32ole'

xl = WIN32OLE.connect('Excel.Application')
ws = xl.ActiveSheet

range = ws.Range('C3:F5')

pic = ws.Shapes.AddPicture( {
'FileName' => 'C:\Pictures\Image1.jpg',
'LinkToFile' => false,
'SaveWithDocument' => true,
'Left' => range.Left,
'Top' => range.Top,
'Width' => range.Width,
'Height' => range.Height
} )


You can find further details on the AddPicture() method on MSDN.

My thanks to Charles Roper for his inquiry, prompting me to dig a little deeper.

And my thanks to you for stopping by!

Sunday, August 2, 2009

OCR: Converting Images to Text with MODI

Joe Schmoe from Kokomo has a scanned image of a 300-page contract. Joe wishes he could search this file for certain rates and terms, but it's an image, not a text file. OCR might be just what the doctor ordered.

Optical character recognition, usually abbreviated to OCR, is the mechanical or electronic translation of images of handwritten, typewritten or printed text (usually captured by a scanner) into machine-editable text. --Wikipedia

One such OCR solution that you may already have available to you is Microsoft Office Document Imaging (MODI), part of the Microsoft Office suite. Let's look at how you can use Ruby and the MODI API to automate the conversion of a scanned document into text.

Installing MODI


MODI might not have been installed when you installed Microsoft Office, so your first step may be to install it from the Office install disks. If installed, you will probably find an icon for "Microsoft Office Document Imaging" located on your Windows Start/Programs menus under "Microsoft Office Tools". If it's not there, go to your Add/Remove Software control panel, select your Microsoft Office installation, and select the option to add features. Then follow the necessary steps, which may vary depending on your version of Windows and Office.

Accessing the MODI API

To begin with, we'll use the win32ole module to create a new instance of the MODI.Document object:


require 'win32ole'
doc = WIN32OLE.new('MODI.Document')

Loading the Image

The next step is to call the document object's Create() method, passing it the name of the .TIF file to load:

doc.Create('C:\images\image1.tif')

NOTE: MODI only works with TIFF files. If your image is in another format (.JPG or .PNG, for example), you can use an image editor (such as Paint.NET or Photoshop) or code library (such as RMagick) to convert it to TIFF format.

Performing the OCR

The OCR() method performs the optical character recognition on the document. The mthod can be called without parameters...

doc.OCR()

...or with any of three optional parameters:

doc.OCR( { 'LangId' => 9,
'OCROrientImage' => true,
'OCRStraightenImage' => true } )

LangId: An integer representing the language of the document. English = 9, French = 12, German = 7, Italian = 16, Spanish = 10. This value defaults to the user's regional settings.

OCROrientImage: This boolean value specifies whether the OCR engine attempts to determine the orientation (portrait versus landscape) of the page. The value defaults to true.

OCRStraightenImage: This boolean value specifies whether the OCR engine attempts to "deskew" the image to correct minor misalignments. The value defaults to true.

You may find that tweaking these parameters from their default values produces better results, depending on the individual image(s) you're working with.

Getting the Text

Naturally, you'll want to get your hands on the text produced by the OCR process. Each page of the Document is represented by an Image object. The Image object contains a Layout object; and that Layout object's Text property represents the text for that image/page. So the hierarchy looks like this:

Document
=>Images
=>Image
=>Layout
=>Text

To accrue the entire text, simply iterate over the Document.Images collection and grab the Layout.Text values. For example:

File.open('my_text.txt', 'w') do |f|
for image in doc.Images
f.puts("\n" + image.Layout.Text + "\n")
end
end

Text, But Not Formatting

No OCR process can guarantee 100% accuracy, but I've found that MODI does a pretty good job recognizing text. Results will vary, of course, depending on the quality of the TIFF image. Note, however, that it cannot preserve formatting of tabular data. So while the text in a series of columns may be produced with a high degree of accuracy, that text will probably be produced with one value per line. So...

apple orange pear

...comes out as...

apple
orange
pear

Paragraphs of text have, in my experience, been produced with the proper line feeds. Play around with it and see if it meets your needs.

That concludes our show for today. Thanks for tuning in!

Sunday, July 12, 2009

Ruby & Excel: Inserting Pictures Into Cells

A reader recently asked how to insert an image from their PC into a cell in an Excel worksheet. So if you have a couple of minutes, I'll demonstrate how to insert an image, specify the exact position, and resize the image.

UPDATE: It seems that the Worksheet.Pictures.Insert() method that I demonstrated below, though frequently used, is not actually officially documented in the Excel Object Model Reference. See this newer article for the officially documented method.

Let's start by connecting to an open Excel worksheet:


require 'win32ole'
xl = WIN32OLE.connect('Excel.Application')
ws = xl.ActiveSheet

Inserting the Image

To insert a picture into a worksheet, call the Worksheet object's Pictures.Insert() method, passing it the filename of the image to insert:

pic = ws.Pictures.Insert('C:\Pictures\Image1.jpg')

The Pictures.Insert() method inserts a new Picture object into the Pictures collection and returns a reference to the new Picture object, which we've assigned to the variable pic.

Positioning the Image

OK, now that you've got the picture inserted into the worksheet, you probably want to specify its exact position, perhaps aligned with a certain range of cells. Let's start by defining that range of cells, from cell C3 to cell F5:

range = ws.Range('C3:F5')

We want the picture aligned with the top/left corner of our range, so we'll set our Picture object's Top and Left properties to be the same as our Range object's Top and Left properties.

pic.Top = range.Top
pic.Left = range.Left

Resizing the Image

Now that we have the top/left position set, let's move on to specifying the width and height of the picture. The original image has an aspect ratio, which is the image's width divided by its height. An image that is 800x600 pixels could be said to have an aspect ratio of 4:3. When resizing an image, you may wish to maintain its original aspect ratio, to avoid making the image appear stretched in one direction or the other.

By default, a Picture object in Excel has its aspect ratio locked, so that when you change either the width or the height, the other dimension is automatically adjusted to preserve the aspect ratio.

You adjust the width and/or height of a Picture object by setting its---wait for it---Width and Height properties. With the aspect ratio locked, we can set the image to fill the width of the range...

pic.Width = range.Width

...or to fill the height of the range...

pic.Height = range.Height

...but we cannot successfully apply both settings without first unlocking the aspect ratio.

To unlock the Picture's aspect ratio, you set the Picture object's ShapeRange.LockAspectRatio property to false:

pic.ShapeRange.LockAspectRatio = false

Now that we have unlocked the aspect ratio, we can set the picture's width and height to match the range's width and height:

pic.Width = range.Width
pic.Height = range.Height

The Width and Height properties are just numerical values. So you could instead do something like this:

pic.Width = 400
pic.Height = 300

And that, my friends, is how you insert, position, and resize an image in Excel.

Let me know if you have any questions or comments, and thanks for stopping by!

Thursday, July 9, 2009

Ruby & Excel: Hiding and Unhiding Columns, Rows, and Worksheets

Occasionally, when working with Excel, you may have a need to hide certain columns or rows in a worksheet. As an example, perhaps your worksheet lists revenue for each of 12 months, but your intended recipient only wants to see the columns showing year-to-date totals. Whatever the reason, you'd like to simply hide certain columns (or rows) rather than delete them completely. And since you're here, you'd probably prefer to do that with Ruby code...

Let's set the scene by assuming that your code is working with an open workbook and you want to hide columns in the currently selected worksheet:


require 'win32ole'
xl = WIN32OLE.connect('Excel.Application')
wb = xl.ActiveWorkbook
ws = xl.ActiveSheet

Hiding Columns

To hide one or more columns, obtain a reference to the column range(s) and set the Hidden property to true:

ws.Columns('A').Hidden = true
ws.Columns('D:K').Hidden = true

Unhiding (displaying) columns works the same way; except, of course, you set the Hidden property to false:

ws.Columns('A').Hidden = false
ws.Columns('D:K').Hidden = false

The following code ensures that all columns in a worksheet are visible:

ws.Columns.Hidden = false

Hiding Rows

Rows have a Hidden property, too, so you can do this to hide rows...

ws.Rows('3').Hidden = true
ws.Rows('7:11').Hidden = true

...and to unhide them:

ws.Rows('3').Hidden = false
ws.Rows('7:11').Hidden = false

Hiding Worksheets

But what if you want to hide an entire worksheet? The Worksheet object doesn't have a Hidden property. Instead, you'll use the Visible property. So to hide the 'Great Amish Scientists' worksheet in the active workbook (wb), we'd use this code:

wb.Worksheets('Great Amish Scientists').Visible = false

And to unhide it, we'd toggle the Visible property back to true:

wb.Worksheets('Great Amish Scientists').Visible = true

The following code ensures that all worksheets in a workbook are visible:

wb.Worksheets.each do |ws|
ws.Visible = true
end

And that, folks, is pretty much all there is to it. Let me know if you have any questions or comments, and thanks for stopping by!

Sunday, June 28, 2009

wxRuby: Changing Text Fonts and Colours

A reader recently asked me how to change the text font size and color for wxRuby controls such as the StaticText control. Let's take a look at how you can do this.

Imagine, if you will, that we have a StaticText control named my_control...

Changing Fonts

We'll begin by creating a new Font object by calling the Font.new() method:


my_font = Wx::Font.new()

Next, we'll set various attributes of our new Font object:

my_font.set_point_size(20)
my_font.set_family(Wx::FONTFAMILY_MODERN)
my_font.set_style(Wx::FONTSTYLE_ITALIC)
my_font.set_weight(Wx::FONTWEIGHT_BOLD)

Once we have our Font object defined to our satisfaction, we can then pass it to our control's set_font() method:

my_control.set_font(my_font)

Changing Colors

Text color is not an attribute of the Font object, but is rather the foreground color of the control. So, to change the color of the text, we call the control's set_foreground_colour() method and pass it a Colour object. We'll make it easy and use one of wxRuby's built-in Colour constants:

my_control.set_foreground_colour(Wx::RED)

Make a note of the spelling: colour, not color.

Further Reading

A simple working example can be found here.

Documentation of the Font object can be found here.

Documentation of the set_foreground_colour() method can be found here.

Documentation of the Colour object can be found here.

And there you have it. Let me know if you'd like to see more on this or other subjects.

Thanks for stopping by!

Tuesday, June 23, 2009

Ruby & Word: Inserting Tables

Microsoft Word is great for text documents. Microsoft Excel is great for tables of data. But, sometimes, you need to get your chocolate in your peanut butter. In other words, you may occasionally need to include a table in a Word document. Let's walk through how to do that.

Setting the Stage

To borrow an example from my upcoming book, let's say that you want to insert a table that contains a list of all movies starring Spencer Tracy and Katharine Hepburn, including the year each movie was released, the title, and the director. Your 2-dimensional films array might look like this:


films = []
films << ["1942", "Woman of the Year", "George Stevens"]
films << ["1942", "Keeper of the Flame", "George Cukor"]
films << ["1945", "Without Love", "Harold S. Bucquet"]
films << ["1947", "The Sea of Grass", "Elia Kazan"]
films << ["1948", "State of the Union", "Frank Capra"]
films << ["1949", "Adam's Rib", "George Cukor"]
films << ["1952", "Pat and Mike", "George Cukor"]
films << ["1957", "Desk Set", "Walter Lang"]
films << ["1967", "Guess Who's Coming to Dinner", "Stanley Kramer"]

Let's connect to a running instance of Word and use the currently selected document:

require 'win32ole'
word = WIN32OLE.connect('Word.Application')
doc = word.ActiveDocument

Moving to the End of the Document

First, let's move to the end of the document, where we'll add our new table. We do this by calling the Selection.EndKey() method, which moves the selection to the end of a word, line, or document. We'll pass this method a value of 6, which specifies that we want to move to the end of the document:

word.Selection.EndKey(6)

Adding a New Table

The Tables collection in Word's object model represents all the Table objects in a selection, range, or document. To add a new Table to a document, call the Document object's Tables.Add() method and pass it three parameters:

* The range object representing where the table is to be inserted
* The number of rows for the new table
* The number of columns for the new table

Now let's add a new table with one row and three columns (we'll add more rows later):

table = doc.Tables.Add(word.Selection.Range, 1, 3)

The Tables.Add() method returns a reference to the newly created table, which we have assigned to the cleverly named variable table.

Inserting Text into Table Cells

You can reference a single cell in a table by calling the Cell() method and passing it the row and column numbers (NOTE: the first row or column is represented by 1, not 0). Once you have your cell, you can set the text via its Range.Text property; so we add the header text as follows:

table.Cell(1, 1).Range.Text = 'Year'
table.Cell(1, 2).Range.Text = 'Film Title'
table.Cell(1, 3).Range.Text = 'Director'

Adding Rows

To add a row to your table, simply call the Table object's Rows.Add() method. Now that we've added the header text, let's iterate over our films array and add a new row to the table for each film and insert the text:

films.each_with_index do |film, r|
table.Rows.Add()
film.each_with_index do |field, c|
table.Cell(r + 2, c + 1).Range.Text = field
end
end

There you have it. Thanks for stopping by!

Friday, June 12, 2009

Ruby & Word: Counting Words and Pages

Someone recently asked how to get a count of the number of words and pages in a Microsoft Word document. This is done by calling the ComputeStatistics() method on a Range or Document object.

As an example (play along at home), let's imagine that you have a Word document open. Your first step is to use the win32ole library's connect() method to connect to the existing instance of Word:


require 'win32ole'
word = WIN32OLE.connect('Word.Application')

You pass the ComputeStatistics() method an integer representing the type of statistic that you want to calculate. In other words, "What do you want to count?" So let's take a moment to define constants for those values:

WdStatisticCharacters = 3
WdStatisticCharactersWithSpaces = 5
WdStatisticWords = 0
WdStatisticLines = 1
WdStatisticParagraphs = 4
WdStatisticPages = 2

You can call the ComputeStatistics() method on a Document object...

doc = word.ActiveDocument
word_count = doc.ComputeStatistics(WdStatisticWords)
page_count = doc.ComputeStatistics(WdStatisticPages)

...or on a Range object...

paragraph = doc.Paragraphs(27)
word_count = paragraph.Range.ComputeStatistics(WdStatisticWords)
char_count = paragraph.Range.ComputeStatistics(WdStatisticCharacters)

When called on a Document object, the method accepts an optional second parameter, IncludeFootnotesAndEndnotes, a boolean which (obviously) specifies if the calculation should include footnotes and endnotes:

word_count = doc.ComputeStatistics(WdStatisticWords, true)

The IncludeFootnotesAndEndnotes parameter defaults to false.

Official details on the ComputeStatistics() method are available from MSDN here.

That's all for now. Thanks for stopping by!