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Posted 9 Mar 2003


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Thumbnail Generator - An easy way to process thumbnails from a large amount of images

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4.85/5 (15 votes)
9 Mar 20031 min read
Thumbnail Generator application supporting a bunch of image file types (for both: source images and target thumbnails), fixed target image size as well as ratio calculation, and full internationalization.

Sample Image - ThumbGenerator/ThumbGenerator.png


I have always had problems generating thumbnails from a large amount of images quickly and easily. Also standard graphic programs couldn't meet my needs - or it simply took too much time handling image after image.


This Thumbnail Generator is qualified for generating thumbnails of images you are publishing on the Internet. Pre-generated thumbnails save you processor utilization and disk space (if you're generating thumbnails on the fly) - or user's time and money.

But also converting a large amount of images from one file format to another can be handled easily.

This project might also be an interesting starting point for Win Form rookies. Learn how forms, simple internationalization support and XML are working together! Just download the project source code, all source files are commented.


Image support

  • Different file formats (BMP, GIF, JPEG, PNG, TIFF) - for both: source images and target thumbnails
  • Self specified thumbnail image extensions
  • Preview of source images and output thumbnails (including information on width, height, ratio)
  • Fixed width, height as well as maintaining aspect ratio
  • Bilinear re-sampling

Generating a ListBox item:

/* Retrieve image to get it's infos */
Image LbxSourceImage = Image.FromFile(filesFromDialog[i]);

/* Calculate image ratio */
float Ratio=((float)LbxSourceImage.Width)/((float)LbxSourceImage.Height); 

/* Generates Listboxitem */
ImageListBoxItem lbxItem = new ImageListBoxItem(
    filesFromDialog[i].ToString()+                /* Filename */
    "\r\n"+txtWidth+LbxSourceImage.Width.ToString()+    /* Width    */
    ", "+txtHeight+LbxSourceImage.Height.ToString()+    /* Height   */
    ", "+txtRatio+Ratio.ToString(),i);            /* Ratio    */


Multilingual support

Also full multilingual support for English and German language is provided. (Feel free to contribute other translations ;) )

Internationalization is managed via XML. All GUI texts are read on startup, from the application configuration file (of course the language can also be changed during a session). The project includes a collection of useful methods for processing XML documents. You can easily use them for your own applications.

The configuration file looks like:

<?xml version="1.0" encoding="UTF-16"?>
<!DOCTYPE Application SYSTEM "Config.dtd">
    <Name>Thumbnail Generator</Name>
  <StdLanguage Type="en"/>
  <Language Type="en">
    <Text GUIRelation="btnGenerateThumb">Generate Thumbnails --></Text>
    <Text GUIRelation="gbxSource">Source:</Text>


  <Language Type="de">
    <Text GUIRelation="btnGenerateThumb">Generiere Thumbnails --></Text>
    <Text GUIRelation="gbxSource">Quelle:</Text>
    <Text GUIRelation="gbxTarget">Ziel:</Text>



Within the application the language information is fetched via XPath. Sample calls:

XPathDocument XPathDoc = new XPathDocument(configFileName);
XPathNavigator nav     = XPathDoc.CreateNavigator();

gbxSource.Text = XmlManager.GetValueFromXPath(nav, 
gbxTarget.Text = XmlManager.GetValueFromXPath(nav, 


  • 09. March 2003: Initial release. See section "Supports"


This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


About the Author

Christian Ballerstaller
Web Developer
Germany Germany
- Java
- C#
- Server administration

- ASM, Visual Basic (poor)
- Linux (poor)

If you have any offers, questions, or project ideas please feel free to contact me.

If you experience any bugs in my software, please report them.

Thank you.

Comments and Discussions

GeneralSmall error in your demo with Maintain aspect with height specified Pin
maildlee31-Jan-10 19:46
Membermaildlee31-Jan-10 19:46 
Generalsending the Image to another function Pin
dogmatic697-Nov-07 2:43
Memberdogmatic697-Nov-07 2:43 
GeneralHere's the spanish translation and some comments Pin
bauersachs11-Dec-06 3:08
Memberbauersachs11-Dec-06 3:08 
Generaldelete files that add to imageList box Pin
nazli28-Aug-06 3:22
Membernazli28-Aug-06 3:22 
seapigg16-Jul-06 6:47
Memberseapigg16-Jul-06 6:47 
Generaluse ratio to make images look better Pin
djohnson1496-Dec-05 2:55
Memberdjohnson1496-Dec-05 2:55 
GeneralI-Load - thumbnail generator free component Pin
zioturo3-Nov-05 0:59
Memberzioturo3-Nov-05 0:59 
GeneralA generic error occurred in GDI+ Pin
Paul Novelli9-Jul-05 6:11
MemberPaul Novelli9-Jul-05 6:11 
GeneralRe: A generic error occurred in GDI+ Pin
dogmatic697-Nov-07 2:25
Memberdogmatic697-Nov-07 2:25 
Questionsource of the dll?? Pin
mistery2218-Oct-03 8:51
Membermistery2218-Oct-03 8:51 
GeneralCannot find file exception Pin
Huang, XiaoTian20-Apr-03 17:48
MemberHuang, XiaoTian20-Apr-03 17:48 
QuestionControls library? Pin
Todd Smith11-Mar-03 4:20
MemberTodd Smith11-Mar-03 4:20 
AnswerRe: Controls library? Pin
perlmunger11-Mar-03 9:53
Memberperlmunger11-Mar-03 9:53 
GeneralRe: Controls library? Pin
Christian Ballerstaller11-Mar-03 10:06
MemberChristian Ballerstaller11-Mar-03 10:06 
Generalirfanview Pin
Wilhelm Berg10-Mar-03 21:28
MemberWilhelm Berg10-Mar-03 21:28 
GeneralRe: irfanview Pin
Christian Ballerstaller11-Mar-03 10:12
MemberChristian Ballerstaller11-Mar-03 10:12 
GeneralRe: irfanview Pin
jstephenson177122-Jan-04 15:23
Memberjstephenson177122-Jan-04 15:23 
GeneralRe: irfanview Pin
Todd C. Gleason16-Nov-04 13:51
MemberTodd C. Gleason16-Nov-04 13:51 
GeneralRe: irfanview Pin
Rowland Shaw29-Dec-05 3:14
MemberRowland Shaw29-Dec-05 3:14 
GeneralRe: irfanview Pin
Dermot O S26-Oct-07 1:29
MemberDermot O S26-Oct-07 1:29 

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