Class: HumanReadableImageGenerator

• Inheritance
• Description
• Class protocol
  • defaults
  • image specs
  • instance creation
  • support
• Instance protocol
  • accessing
  • initialization
  • private
  • public
• Examples

Inheritance:

   Object
   |
   +--HumanReadableImageGenerator

Package:

stx:goodies/webServer

Category:

Net-Communication-HTML-Misc

Version:

rev: 1.21 date: 2021/11/26 17:58:20

user: cg

file: HumanReadableImageGenerator.st directory: goodies/webServer

module: stx stc-classLibrary: webServer

Description:

Generate a form containing a string for the user to type into a web-form
as confirmation that he is really human.
I.e. the forms image is designed to make it hard for an OCR program to
extract the characters.
At least, we hope that it is so.

Sometimes, the picture is hard to decipher, even for a real human;
therefore, add some 'try another picture' button to the web page.

Caveat: this is a dirty hack

[usage:]
    HumanReadableImageGenerator new generate inspect

copyright
COPYRIGHT (c) 2008 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 characterMapCharacters

 numberOfCharMaps

 charMapImage1

character bitmaps (needed ebcause the webServer has no Display for drawing)

Usage example(s):

self charMapImage1 inspect ImageEditor openOnClass:self andSelector:#charMapImage1 Icon flushCachedIcons

 charMapImage1_height

 charMapImage1_width

 charMapImage2

character bitmaps (needed because the webServer has no Display for drawing)

Usage example(s):

self charMapImage2 inspect ImageEditor openOnClass:self andSelector:#charMapImage2 Icon flushCachedIcons

 charMapImage2_height

 charMapImage2_width

 charMapImage3

character bitmaps (needed ebcause the webServer has no Display for drawing)

Usage example(s):

self charMapImage3 inspect ImageEditor openOnClass:self andSelector:#charMapImage3 Icon flushCachedIcons

 charMapImage3_height

 charMapImage3_width

 getCharMapImage: idx

self getCharMapImage:1
self getCharMapImage:2
self getCharMapImage:3

 new

(comment from inherited method)
return an instance of myself without indexed variables

 fonts

 generateFontMaps

generates the methods:
charMapImage1,
charMapImage2,
...
one for each font

Usage example(s):

self generateFontMaps

 generateImageMethod: selector with: image forFont: aFont

self generateFontMaps

Instance protocol:

 characterSet: something

 colors: aCollectionOfColors

 extent: aPoint

 maxAngle: something

 minAngle: something

 numberOfRandomDots: anInteger

 numberOfRandomLines: anInteger

 string

 string: something

 stringLength: something

 computeExtent

what a hack

 generateString

 initialize

|gen image|

gen := HumanReadableImageGenerator new.
gen numberOfRandomDots:5000.
gen numberOfRandomLines:10.
gen minAngle:-45.
gen maxAngle:45.
image := gen generate.
image inspect.

 randomCharacter

 generate

HumanReadableImageGenerator new generate inspect

 generateFormUsingDisplay

ensure that even after rotation, the result still lies inside the charBox.

Usage example(s):

HumanReadableImageGenerator new generateFormUsingDisplay inspect

 generateImageWithoutUsingDisplay

colors := OrderedCollection new.

Usage example(s):

HumanReadableImageGenerator new generateImageWithoutUsingDisplay inspect

 generateImage

Examples:

    |gen image|

    gen := HumanReadableImageGenerator new.
    gen extent:300@100.
    gen numberOfRandomDots:1000.
    gen numberOfRandomLines:25.
    gen minAngle:-45.
    gen maxAngle:45.
    gen string inspect.
    image := gen generate.
    image inspect.