Daily working on a computer, we deal with a lot of graphic files. It seems so habitual and natural, what even on a simple question « what first graphic representation appears after inclusion of a computer? » many peoples would respond, what is it – Windows logo, not paid attention to emblem BIOS.
For a conclusion graphic on the screen the huge quantity of formats has been thought up. We think, will not be a mistake if to say, that the greatest quantity of images is written down in JPEG format.
Each time at loading pages Internet Explorer or other browser on the screen there are photos and figures which represent files with expansion JPEG. Practically all modern digital cameras save pictures in this format. The reason of so high popularity of standard JPEG is obvious - the small size and high quality which can achieve at preservation schedules in this format. Thus a parameter the size/quality at JPEG practically is always better, than at any other graphic format.
The full name of this format means Joint Photographic Experts Group. It is the name of the commission made of representatives of the organizations on standardization International Telecommunications Union (ITU) and International Organization for Standartization (ISO) and organized specially for development of a way of compression of images.
For creation of images in format JPEG many bulky editors raster use schedules, such as Photoimpact, Photopaint, Photoshop and others. However, if your basic employment - preparation of images for the Internet, you can manage a set of the small utilities intended specially for preservation of pictures in format JPEG. On the one hand, it will save charges on purchase of a software, on the other hand, they are more simple in development, than serious graphic editors, and often have more than specialized tools.
Unjpeg 1.5
Miracles in world does not happen - if file JPEG has the small size, quality of the image to a greater or lesser extent suffers. Falling of quality depends on algorithm of compression of the image. This algorithm is based that for normal visual recognition of a picture it is possible to lower accuracy of the passed image partially.
At preservation of data in format JPEG the picture is translated from color model RGB in another - YCbCr. If in case of with RGB the image is set by three components of color in system YCbCr a key role play the channel with the information on brightness and two making colors. Such model of representation schedules most precisely meets to physiological feature of human sight as for color model YCbCr it is more important than a component of brightness color. Can check up this statement - try to recognize correctly in twilight color, and you will see, what is it much more difficultly, than in the afternoon.
The image on each of channels shares on square sites eight on eight pixels. To these sites it is applied discrete cos. transformation then the received factors are exposed to quantization and are packed by means of codes Haffmans. At this stage also there is most a big loss of quality of a picture. As high-frequency factors are exposed to stronger quantization, than low-frequency, on the image there are artefacts, and fine details vanish. Than degree of compression more, factors are exposed to especially strong quantization all.
At strong degrees of compression there are unpleasant blocks on the image which especially are evident on those sites of a picture where is gradient transition.
People whom in editing raster schedules professionally are engaged, know the certain receptions by means of which in Photoshop or other editor the image can be corrected, having removed not only “ block effect ”, but also some artefacts in the form of spots and indistinct sites.
Utility Unjpeg allows to execute quickly and qualitatively all this, and, for this purpose it is even not necessary to select options. It is enough to open the image in the program, and in a window of preliminary viewing already processed picture or figure, with options by default will be displayed.
In Unjpeg there are various structures for elimination of a different degree of artefacts. Options of the program can be divided conditionally on two basic groups: what are responsible for removal of sharp transitions between blocks, and options of the filter for prompting sharpness. Besides in the program two methods of search of artefacts on the image are incorporated: heuristic algorithm of detection of artefacts and a standard method of the analysis of the image with use of the information in heading of a JPEG-file. Search of artefacts will differ also depending on type of the image - whether this file represents badly saved figure, whether it is unsuccessfully compressed photo.
Also in Unjpeg there is an additional filter for elimination of casual noise. The unique minus of the program - function “Undo” works only for the filter against noise of the image.
The program extends as shareware. The demo can be downloaded from an official site.
JPEG Wizard 2.4
Certainly, elimination of artefacts on the image it is good but how to be, if the image needs to be processed filters, for example, to make effect of the photograph which have turned yellow from an old age or to execute color correction? It is not necessary to catch again for Adobe Photoshop, look narrowly better at small utility JPEG Wizard. He/she is the tiny graphic editor who is focused exclusively on job with files JPEG.
This program can carry out all functions on editing the image - to cut off edges, to change the sanction, to correct a colour rendition, to delete red eyes effect, to turn a picture and even to create collages on the basis of the chosen pictures. In JPEG Wizard it is very convenient to observe of the size of a final file which is automatically recalculated by the program each time after this or that operation with the image has been executed.
JPEG Wizard has more than forty filters with various effects, that, in general, are not much less, than in the same Photoshop. The program allows to import files from digital chambers and scanners. Besides by means of the given utility it is possible to make screenshots of any area of the screen. In case it is required to edit at once the big number of files, in JPEG Wizard there is a module of batch operation Batch Editor.
The program extends as shareware. The demo can be downloaded from an official site.
Advanced JPEG Compressor 5
Export of images to format JPEG is very important stage of editing of images, in fact from what options of compression will be specified, the graphic file can turn out too big or, on the contrary, small, but with unsatisfactory quality. Many programs for processing images do not allow to make thin option of a target file.
Basic applicability Advanced JPEG Compressor - compression of images in format JPEG. The program has the big number of parameters which influence an end result. For example, here is special four-line an equalizer of quality by means of which it is possible to set parameters of a compression separately for larger objects and fine details on the image. Besides it is possible to operate a compression of each of channels of color model.
Advanced JPEG Compressor supports also a compression lost-free, however at job in this mode the set of opportunities is limited. The size of a file in this case can be reduced only due to removal of the EXIF-information, change or removal of invisible text comments.
On a picture it is possible to add watermarks, and also to carry out base operations of editing: to operate color scale, to increase clearness, to turn, change contrast, etc.
As the program supports set of formats, it can be used as the converter of graphic files. Advanced JPEG Compressor it is integrated into environment Windows and can be started from the context menu.
The program extends as shareware. The demo can be downloaded from an official site.
Result
The programs similar described above, necessarily should be near at hand at a web-masters and simply at amateurs share photos through the Internet with friends. Often much easier quickly to open a graphic file in such small utility to improve its quality, to add watermark or to transform in JPEG, than to wait, while it will be loaded Photoshop with all filters and to think, what of them to apply. And if you are not strong in Photoshop, risk to spend a lot of time, searching for an option of batch operation of files and deliberating how to save a file in JPEG with the least losses.
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