On PHPMaster.com today there's a new post highlighting the use of pChart to graph out the data from your PHP application. pChart provides an easy interface to draw graphs with GD, supporting alpha transparency, shadowing, spline/cubic curves and much more.

Created and maintained by Jean-Damien Pogolotti, a systems engineer based in Toulouse, France, pChart is a library that creates anti-aliased charts and graphs using PHP. It's object-oriented code has been recently redesigned and makes it easy to add beautiful, eye-catching data. The library is free for non-profit use and for inclusion in GPL distributed software; licensing plans for other uses start at just 50 Euro. In this article I'll take you through installing pChart and using it to generate a basic chart, line chart and plot graph.

He walks you through the download and installation of the tool as well as showing the code you'll need to include to get started with a first script. Their examples show how to create both single- and three-series charts with some sample data and some screenshots of output.

On Script-Tutorials.com there's a new tutorial posted showing you how you can get better curves on your graphs with PHP and GD (the key is in the "CubicSplines" class, providing a few extra calculations to make "splines", a mathematical method for smoothing out values).

Today I have new article for PHP. I will tell you about drawing graphs with GD. Plus - we will smooth our graph with curve lines using cubic splines interpolation method. You can read more about method at Wikipedia.

All of the code is included in the post, ready for cop and pasting - the HTML, CSS plus the PHP to generate the graph, plot the points and apply the cubic splines values. You can check out a live demo of it in action or just download the code and get started on your own.

On the .net magazine site (yes, really) there's a recent post from Brian Suda about creating SVG images with PHP thanks to the GD functionality that's included in every release.

If you're working online, then canvas springs to mind. It allows you to draw raster graphics quickly and easily. If you want, there are also plenty of image code libraries that can generate GIFs, JPEGs and PNGs on request. But what if your target isn't always online? What if you're aiming for print? Then you could use a raster graphic, but it would need to be pretty large. A better solution is to create a vector-based image format from your code. This is where SVG (Scalable Vector Graphics) steps in.

He starts by explaining a bit about SVG and what it is for those that haven't worked with it before. He givesn an example of a poster from Wired showing circles with colors from their covers over the last 15 years. He shows how to do something similar with images of the .net magazine covers, pulling out the color frequency with the imagecolorat function. Toss in a bit of markup and some formatting of the color output and you'll get circles with concentric rings with the most prominent colors ending up the largest. You can see his result here.

On the Script-Tutorials blog today there's a new tutorial posted showing you how to easily add watermarks to your images dynamically, either as a part of a cache generation or on upload.

I will show you how to use GD library. And, main task today is adding watermark to image and generate result as PNG image into browser. We will using PHP and GD library. This is nice library to work with images at server side. Also (as additional tasks) I will draw little frame over image and will draw some text. Between, you can use this method (of adding watermarks in realtime) to protect original photos.

Full code for the script is included in the post, showing the combining of two images into the one finished product. The code is also available for download if you'd like to get hacking right away.

In a new post to his blog Philip Norton shows how to desturate images with PHP using the already built-in GD libraries and the imagecopymergegray function.

To desaturate an image means to remove all non-greyscale colours from it, essentially creating a black and white version. To do this you can use the function imagecopymergegray(), which is part of the GD image library. This function is a little difficult to figure out, but what is does is sample one image into another and optionally changing the amount of colours that are kept during the sampling process. The function can be made to sample just a section of the image, or the whole thing.

He also offers an alternative method that uses imagefilter instead, passing it the IMG_FILTER_GRAYSCALE flag. Included is a full block of code for a method he recently included in a WordPress site to dynamically create thumbnails.

Sameer Borate has posted a simple method for creating a color palette from a given image using just PHP and GD.

In the previous post we saw how we can generate a screenshot from a url. In this post we will see how we can create a color palette of the screenshot (or any other image for that matter) using PHP and GD. This can be useful if you need to quickly get the color scheme of a website or a image. Below are a few example images and their palettes generated using the program.

With the help of his code it's as easy as a call on a GetMostCommonColors object (get_color) to return the hex codes for the values found most. Also included in the post is a sample snippet showing how to pull the details from the file and output it in a grid similar to this.

Smashing Magazine has a new post today about using jQuery and GD to manipulate images to upload an image, crop it and save that version to the remote server.

One of the numerous advantages brought about by the explosion of jQuery and other JavaScript libraries is the ease with which you can create interactive tools for your site. When combined with server-side technologies such as PHP, this puts a serious amount of power at your finger tips. [...] Sure, there are plugins out there that you can use to do this; but this article aims to show you what's behind the process. You can download the source files for reference.

They walk you through the little bit of setup you'll need before things will be working and then move right into the upload form and PHP handling that goes with it. The Javascript that goes with it is all home-grown (not a plugin) and cleverly uses a DIV to simulate the bounding box for the crop.

New from NETTUTS.com there's a recent tutorial showing you how to use the GD graphics library (bundled with PHP) to resize images on the fly.

Ever wanted an all purpose, easy to use method of resizing your images in PHP? Well that's what PHP classes are for '" reusable pieces of functionality that we call to do the dirty work behind the scenes. We're going to learn how to create our own class that will be well constructed, as well as expandable. Resizing should be easy.

The simple eleven-step process (don't worry, it sounds worse than it is) has you go from a basic image and, with the help of a custom PHP class, create a resized image based on a type such as "landscape", "auto" or "exact". Full code is included for you to cut and paste or you can download the source and have the full code ready and waiting.

On PHPBuilder.com today there's a new tutorial posted helping you create a simple CAPTCHA image you can use in your forms to help to somewhat secure them from scripts out there that might abuse them.

CAPTCHA protection is used on web site forms and works by generating a random string, writing it to an image, then storing the string inside of a session. Then, the site checks the CAPTCHA when the form is submitted. In this article, you will learn how to make your own simple CAPTCHA image using PHP. You will create the CAPTCHA image step by step.

Their example uses numbers, lowercase letters and a few other characters to create the distorted image. The tutorial shows you how to take this character set, pull out a few randomized values and push them into a dynamically created image with PHP's built-in GD functionality. They also include a brief script showing how to use it in the form for validation of the submission.

Maurice Svay has a new blog post that includes a script he's developed to perform facial recognition (detect faces in images) with PHP without the need of the Open-CV library.

OpenCV seems to perform well but you need to be able to install it on your server. In my case, I wanted to have a pure PHP solution, so it can work with most hosts. So I started to think about implementing it myself. [...] I kept searching and finally found a canvas+javascript implementation of face detection at http://blog.kpicturebooth.com/?p=8. The code looked fairly compact and simple. Shouldn't be hard to port to PHP.

The class takes in the filename of an image (just JPG, but could easily be adapted) and a data file to use to run the image through the GD image library and output a JPG similar to this with the face highlighted by a red square.