I usually take photos with my digital camera and often download some images from the Internet. Sometimes the photos or images are not the correct direction I want. Of course I can rotate them with some image viewer with rotation function. However, because I open and edit/save JPEG files, they loose quality due to constant re-compression and the results are not make me satisfaction. How should I do? Is there a handy and powerful way to solve this question? Fortunately, I caught sight of a powerful and easy to use tool that supports lossless JPEG rotation. That is JPEGcrop which was published by WebSite. If you have the same troubles as me. JPEGcrop is the best utility that you must have. Below is the detailed introduction of JPEGcrop.
JPEGcrop utilizes beta code of the Independent JPEG Group for lossless cropping of JPEG files and allows us to crop and rotate our JPEG files without quality loss. JPEGclub.org develops new JPEG features and contributes to the Independent JPEG Group (IJG) software. New features and contributions have been developed for the three major parts of the IJG library: the compression, the decompression, and the transcoding parts. These parts are represented by the three major tools of the IJG software: cjpeg (compress JPEG), djpeg (decompress JPEG), and jpegtran (transcode JPEG - lossless). The latest version of JPEGcrop is 2008.01.04. The new features of jpegtran include: Lossless rotation and related transforms. An Exif Patch has been added to the lossless transformation code to avoid some application problems. It is part of the release-candidate croppatch to jpegtran.
A new "-perfect" switch has recently been added to the lossless transformation support in jpegtran. A new"-crop" option has been added to jpegtran for "lossless" cropping of JPEG images. An extended feature set "Lossless crop "n" drop" (cut and paste) has been added to jpegtran. The decompress part of the Independent JPEG Group library has got a direct rescaling feature while decoding with factors 1/2, 1/4, and 1/8. This is interesting because different spatial size output can be retrieved directly from the JPEG (DCT) data without separate full decode and spatial resample. Using a new method, this feature has now been extended to a broader and finer range of scaling factors: All scalings with factors N/8 with N=1...16 (downscale and upscale) are now supported with the djpeg"-scale" option or with setting the scale_num/scale_denom variables in library application. Furthermore, the performance in the old cases (1/2, 1/4, 1/8) has been improved considerably with the new method.
The new features of djpeg include: Two new features have been added to the cjpeg tool and compression library. A new"-scale" option is provided with cjpeg which complements the corresponding djpeg -scale option. The supported range of scaling factors is 8/N with all N=1...16. This means we can now easily alter the nominal spatial resolution of a given source image while compressing to JPEG without additional resampling. For example, if we have an image sensor providing an effective capture resolution of 2268x1512 pixels (HI resolution), you can now directly generate a MED resolution of 1512x1008 pixels (-scale 2/3) and a LOW resolution of 1134x756 pixels (-scale 1/2) from the sensor source resolution with the library while compressing to JPEG without additional resampling.
The Jpegcrop Windows Application was initially developed to provide a convenient interactive user interface for the new jpegtran"-crop" feature. It has now developed to a nearly complete user interface replacement for jpegtran, and furthermore for demonstration of the enhanced djpeg"-scale" feature.
The new features of Jpegcrop include: The most wanted feature currently for Jpegcrop is a "constrained aspect ratio" crop mode. If we need such a function to crop our photo images to the common 10x15 (3:2) photo frame, have a look at Stefan Scherer Jpegcrop with FotoFrame feature. This is a preliminary Jpegcrop extension until an"official" version will be available someday.
JPEGcrop helps you to open and edit/save JPEG files, they loose quality due to constant re-compression. It utilizes beta code of the Independent JPEG Group for lossless cropping of JPEG files and allows you to crop and rotate your JPEG files without quality loss.
1. Jpegtran - scale lossless resize feature
2. Lossless rotation and related transforms
3. Lossless crop n drop (cut & paste)
The license of this software is Freeware, you can free download and free use this image optimizer software.