PHP uses GD library to draw and generate verification code pictures

PHP uses GD library to draw and generate verification code pictures

First you have to determine if the php.ini setting has the GD extension function, test the following

Print_r (Gd_info ());

If there is a printout of the content as follows, then the GD feature is open:

Array (    [GD Version] = bundled (2.0.34 compatible)    [FreeType support] + 1    [FreeType Linkage] = Wit H FreeType    [t1lib support] + 1    [gif Read support] + 1    [gif Create support] + 1    [JPG support] = > 1    [PNG support] = 1    [WBMP support] + 1    [XPM support] =     [XBM support] + 1    [JIS -mapped Japanese Font Support] =)

GD drawing general steps are as follows:

1. Create a canvas resource

2. Create a color brush

3. Drawing

4. Save picture or Output picture

5. Destroying the Memory canvas resource

The test code is as follows:

The test image is as follows:

Note: GD library powerful can draw various reports (such as histogram, pie chart, etc.), thumbnails, watermark and stock charts

Thumbnail function Examples:

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