Applications/Libgd - Revision history

Pysdlb: /* Further Information */

2022-11-16T11:06:41Z

‎Further Information

Pysdlb at 08:32, 5 April 2017

2017-04-05T08:32:19Z

Pysdlb: Pysdlb moved page Libgd to Applications/Libgd without leaving a redirect

2017-03-17T10:20:52Z

Pysdlb moved page Libgd to Applications/Libgd without leaving a redirect

Pysdlb at 09:44, 17 March 2017

2017-03-17T09:44:18Z

Pysdlb at 09:43, 17 March 2017

2017-03-17T09:43:37Z

Pysdlb: Created page with "TOC ==Application Details== *Description: GD is an open source code library for the dynamic creation of images by programmers. GD is written in C, and "wrappers" are avail..."

2017-03-17T09:40:45Z

Created page with "__TOC__ ==Application Details== *Description: GD is an open source code library for the dynamic creation of images by programmers. GD is written in C, and "wrappers" are avail..."

New page

__TOC__
==Application Details==
*Description: GD is an open source code library for the dynamic creation of images by programmers. GD is written in C, and "wrappers" are available for Perl, PHP and other languages. GD creates PNG, JPEG, GIF, WebP, XPM, BMP images, among other formats. GD is commonly used to generate charts, graphics, thumbnails, and most anything else, on the fly. While not restricted to use on the web, the most common applications of GD involve website development.
*Version: 2.2.3 (compiled with gcc)
*Module: gcc/2.2.3
*Licence: GNU

==Usage Examples==

===Module===
<pre style="background-color: #000000; color: white; border: 2px solid black; font-family: monospace, sans-serif;">
[username@login01 ~]$ module add libgd/gcc/2.2.3
</pre>

===Compilation===

'''Libgd'' is a library for use either with a compiled binary that requires it, or it could be required at compilation time also.

A typical code snippet requiring is shown below:

<pre style="background-color: #f5f5dc; color: black; font-family: monospace, sans-serif;">

#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>

void mySavePng(char *filename,
gdImagePtr im)
{
FILE *out;
int size;
char *data;
out = fopen("filename, "wb");
if (!out) {
/* Error */
}
data = (char *) gdImagePngPtr(im, &size);
if (!data) {
/* Error */
}
if (fwrite(data, 1, size, out) != size) {
/* Error */
}
if (fclose(out) != 0) {
/* Error */
}
gdFree(data);
}

</pre>

Compilation is carried out below, in this example the '''gcc''' compiler is used. However, the applies similarly to the Intel compiler too.

<pre style="background-color: #000000; color: white; border: 2px solid black; font-family: monospace, sans-serif;">

gcc -o savePNG savePNG.c -lm -lgd

</pre>

==Further Information==

[https://libgd.github.io/ https://libgd.github.io]

@@ Line 67: / Line 67: @@
 ==Further Information==
-[https://libgd.github.io/ https://libgd.github.io]
+*[https://libgd.github.io/ https://libgd.github.io]
-{|
+{{Librariespagenav}}

← Older revision		Revision as of 08:32, 5 April 2017
Line 68:		Line 68:

	[https://libgd.github.io/ https://libgd.github.io]		[https://libgd.github.io/ https://libgd.github.io]
		+
		+	{\|
		+	\|style="width:5%; border-width: 0" \| [[File:icon_home.png]]
		+	\|style="width:95%; border-width: 0" \|
		+	* [[Main_Page\|Home]]
		+	* [[Applications\|Application support]]
		+	* [[General\|General]]
		+	* [[Training\|Training]]
		+	* [[Programming\|Programming support]]
		+
		+	\|-
		+	\|}

← Older revision		Revision as of 09:43, 17 March 2017
Line 57:		Line 57:

	</pre>		</pre>
		+
		+
		+	==Limitations==
		+
		+	* Very large images can cause gd to run out of memory. And sometimes the image file itself isn't terribly large— consider a JPEG of a completely blank field, 8,000 pixels on a side: the file compresses well but representing it in memory as a bitmap is impractical. If you are coding in PHP, you can check for this situation with the getimagesize function, which determines the image dimensions without using gd. This is possible because the popular image formats all store the image dimensions near the beginning of the file where they are easily accessible. Perl programmers can use the similar Image::Size CPAN module. If you are not using PHP or Perl and your language of choice does not offer a similar feature, you can implement the technique yourself. See the GIF specification, the JPEG specification, and the PNG specification.

← Older revision	Revision as of 10:20, 17 March 2017
(No difference)

@@ Line 15: / Line 15: @@
 ===Compilation===
-'''Libgd'' is a library for use either with a compiled binary that requires it, or it could be required at compilation time also.
+''Libgd'' is a library for use either with a compiled binary that requires it, or it could be required at compilation time also.
 A typical code snippet requiring is shown below: