batch - Arrange JPG images based on JPG compression/quality

16
2014-04
  • Takias

    I have been looking for a way to arrange JPG images based on the quality/compression level of the images.

    I want to do this so that I could select only those images which has less compression (let’s say 90-100%) and batch process them to lower compression level (say 75%) to save hard disk space.

    I have loads of reference images with various compression level. If I apply compression to all the images then the ones with already low compression get reprocessed resulting really lower quality images.

    Does anyone one know how could I select images based on the quality/compression?

    I would really appreciate any help. Takias

  • Answers
  • woliveirajr

    As far as I know, JPEG doesn't stores the "compression amount" inside it.

    Thre is one extension to images, called EXIF, that can store some information about the picture, like the quality. Take a look at this site for some information.

  • Moab

    Close As I could find. Although it may not allow you to arrange them in any way.

    JPEGsnoop reports a huge amount of information, including: quantization table matrix (chrominance and luminance), chroma subsampling, estimates JPEG Quality setting, JPEG resolution settings, Huffman tables, EXIF metadata, Makernotes, RGB histograms, etc. Most of the JPEG JFIF markers are reported. In addition, you can enable a full huffman VLC decode, which will help those who are learning about JPEG compression and those who are writing a JPEG decoder.

    Other potential uses: determine quality setting used in Photoshop Save As or Save for Web settings, increasing your scanner quality, locating recoverable images / videos, decoding AVI files, examining .THM files, JPEG EXIF thumbnails, extract embedded images in Adobe PDF documents, etc.

  • Col

    You should be able to do this by reading the exif information. If you're using windows then microsoft photo info allows exif information to be added to explorer, for newer versions I think it's built in. I'm not sure if this shows the compression as a column though so you may need to find some specialist exif reading software or use an image management tool.


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  • user10056

    I have a file which contains raw pixel data and I want to compress this data using JPEG lossless compression. I tried to search for this tool using google but couldn't fina any. Does anybody know here of any tool which takes raw data as input and compresses it using JPEG lossless format?


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  • Tutul

    XnView, view/convert over 400 graphic file formats (incl. various RAW standards)

    a portable version is also available.

  • nik

    These are starter pointers for Lossless JPEG compression,

    Is there a specific reason for targetting lossless JPEG?
    Would the RAW and other lossless formats not work?

  • Diago

    REA Converter can convert RAW images to various formats, and have a lite edition that is free. THere is also the Contenta RAW Convert however it is not free.