The acronym TWAIN stands for “Technology with No Interesting Name” which translates to “Technology without an Interesting Name”, but actually refers to the standard for imaging and scanning documents. Many of the manufacturers of scanners, digital cameras are part of the field of hardware and software used to handle said documents. We explain how it works and what are the origins of this technology.
What is an image capture device?
To understand the TWAIN standard, the first thing we need to define is what an image capture device is, what it does is capture a snapshot of a specific moment in the real world in digital format. A definition which seems simple, but which is really not because it implies a process at the very least complex which consists of two parts, the first is the capture of the snapshot, the second the transformation into digital signals that can be manipulated by a processor.
If we start from the snapshot, the first thing that comes to mind is a photo, today the photographs are entirely digitized, it is because the CCD, which is the device that captures the image, in is already generating the digital version. processed by a type of processor called an ISP. Although the most veterans of the place or those who work in X-ray scans today will have used a scanner more than once and that is that before the advent of digital photography there was no no other remedy than to use one of these image capture devices to be able to digitize our photographs.
Of course, encoding the data is important, because it is important that all systems that have to work with images understand the same code. The problem is that for a long time each of them spoke a different language, that is, each scanner digitized images in its own way.
What is the TWAIN standard?
We can say that the TWAIN standard is the counterpart of PostScript. And yes, we know it might be a little confusing, but PostScript is a standard that says how a printer should print a document, well, the TWAIN standard does the same, but with scanners and therefore does the job. ‘reverse. . In other words, instead of generating a printed document from a digital file, it generates a digital file via a printed document.
And what is the conversion process for? In principle, one could think of the existence of special equipment that takes care of carrying out the process of creating the digital copy, which would make sense. The reality is that a scanner doesn’t take a full snapshot at once like a digital camera does, because it processes the image in multiple parts, but they share a common element, a CCD sensor. Due to the slowness of image capture and the use of a parallel port that was rather slow in relation to the memory required, the TWAIN standard did not require special processors to digitize the images since its creation in 1992, the CPU was sufficient. .
The other thing in common with PostScript is that scanning uses a common encoding that different TWAIN-compliant programs can understand.
Is TWAIN a type of program?
If we are talking about a program as an executable that can be managed by the user, then the answer is no, but not all system programs are intended for the user and among them is TWAIN.
In many places you will read that TWAIN is the scanner driver, but rather a function within it, the driver simply allows applications to communicate, through the operating system, with the device. in question. Now, as with printers where there is a PostScript program that generates the document in a language that most printers understand, the same thing happens here, but TWAIN is not a program on its own, nor is the driver, that is. rather, is a program for the exclusive use of the image capture driver.
Some more modern scanners, thanks to the use of much faster I / O interfaces than when the standard was created, as well as the integration of the hardware, already include an ISP that literally takes care of the carry out the scanning process internally, store it in a buffer or temporary memory and transmit the image to our computer. As they do? Well, with the same hardware as digital cameras and cell phones.
Its importance in digital cameras
Today the digital camera par excellence is the phone we carry in our pockets, but before it was digital cameras and long before film cameras, which we will not discuss here for obvious reasons.
The hardware that makes a digital camera possible is the same as that of a scanner, i.e. a CCD and the whole scanning system. The difference is that one of the advantages of digital photography is the inclusion of an LCD screen which allows us to see the result of our photographs. Well, the scanning process inside the camera follows the TWAIN standard and the reason is that image manipulation programs must be able to manipulate the results.
Said digitization work is carried out by the FAI or Image Signal Processor, which over time has been digitized to be part of the processor of mobile phones, occupying their small space and today benefiting from neural networks to improve the quality of the photos. captured or specialized accelerators. which are responsible for generating images in specific formats without the intervention of the processor
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