Alpha Channel

Alpha channel......
Few days ago, I wanted to put an image while generating PDF by using FPDF, I got an error that said 'Alpha channel is not supported'. I got stunned and started to think what is it?

In Computer Graphics , Alpha channel is used as an opacity channel. Alpha channel will ensure that how much your image will be transparent or not and it is an additional channel that can be added to an image which contains transparency information about the image. Depending on the type of alpha it can contain various levels of transparency. In PNG/TIFF alpha channel represents up to 256 levels of transparency.

A 32 bit graphics system contains four channels where three 8 bit channel are for Red,Green,Blue (RGB) and one8 bit alpha channel. So alpha channel is simply use of RGB model with extra information. Alpha channel values can be expressed as a percentage, integer, or real number between 0 and 1 like RGB parameters.If a pixel has a value of 0% in its alpha channel, it is fully transparent (and, thus, invisible), whereas a value of 100% in the alpha channel gives a fully opaque pixel .
The following are the file type that support alpha channel:
    * TIFF     * TGA     * PNG     * PSD (Photoshop)     * GIF (special alpha)

Bottleneck

The term 'Bottleneck' that we are going to discuss is not the neck of a bottle rather it tells a different thing. Bottleneck is a phenomenon that impede or slow down the performance of a system. For instance, a computer program may spend 80% of its time in a small loop deep in the code, and the remaining 20% of the time on the rest of the code; the small loop then is a bottleneck. Pertaining to a business, a firm will address the 'bottleneck' that is limiting production. Bottleneck is a familiar terms in every section of knowledge suppose in Engineering, Economics, Project Management etc.

In computer programming, tracking down bottlenecks is called performance analysis. Reduction is usually achieved with the help of specialized tools, known as performance analyzers or profilers. The objective being to make those particular sections of code perform as fast as possible to improve overall algorithmic efficiency.