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Radical Image Optimization Tool (RIOT) by Lucian Sabo

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    #61
    I wanted to make a GIF button, having transparency, a bit smaller.
    If I open the file with RIOT it shows the transparency neatly in both frames with the grey chessboard.
    After doing a resize, the left view shows a 32-bit DIB version, still with the transparent indication.
    But the preview at the right has lost the transparency, and so does the resulting file after a 'save as'.
    If I do the same routine in IrfanView, the transparent mode is still preserved.
    I don't even have to select that color again in the saving dialog.
    0.6180339887
    Rest In Peace, Sam!

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      #62
      What's wrong with this forum ? It was down for days...

      After doing a resize, the left view shows a 32-bit DIB version, still with the transparent indication.
      But the preview at the right has lost the transparency
      This is a known issue.
      Transparency is lost after color quantization.

      After resample 16-bit RGB bitmap are returned as 24-bit. Palettized and 4-bit bitmap are returned as 8-bit palettized images, using an internal conversion to 24-bit followed by a color quantization, or are returned as 32-bit if they contain transparency.
      Resampling refers to changing the pixel dimensions (and therefore display size) of an image. When you downsample (or decrease the number of pixels), information is deleted from the image. When you upsample (or increase the number of pixels), new pixels are added based on color values of existing pixels. You specify an interpolation filter to determine how pixels are added or deleted.
      The following filters can be used as resampling filters:

      Box, pulse, Fourier window, 1st order (constant) B-Spline
      Bilinear filter
      4th order (cubic) B-Spline
      Mitchell and Netravali's two-param cubic filter
      Catmull-Rom spline, Overhauser spline
      Lanczos-windowed sinc filter

      In your case, resampling a 8 bit transparent image results in a 32 bit RGBA image. GIF cannot contain 32 bit data, thus it is quantized to 8bit/256 colors.
      Automatic color quantization is applied, and the color quantization algorithm does not maintain transparency for now.

      For a transparent 8 bit image source, you can see a transparent 8 bit gif result, but reducing colors will lose transparency.
      The same for a 32 bit transparent PNG. If you leave it True Color it will stay transparent. If you reduce colors, the transparency is lost.

      A new version is available
      Here is the changelog:

      v.0.1.7 (stable candidate #4)
      -after resample image was not centered. Fixed
      -Fit to window is now applied on open
      -added option in View menu: Fit in window only big images.
      -change resample form tab order
      -minor code cleanup
      -fixes in Fit to Window
      -actual view is applied after resample
      -drawing speed ups (up to 5 times faster displaying of optimized images)
      -changed about box
      -decreased memory usage.
      -flicker effect on zoom, moving or displaying eliminated
      -new ckeckbox for JPEG and PNG: remove embedded ICC profile
      -MetadataHandler rewrote
      -dragging fix when the mouse cursor is over the other image
      -speed optimizations for Riot Full. Lite version is slightly slower than the full version.
      -compiler optimizations
      -RIOT full is now capable of displaying jpeg and bmp in the small preview area of the open dialog
      Lite version supports only bmp preview
      -removed emf and wmf from the supported file types for now
      -on high resolution images (>=4 MegaPixels) the user is asked if he wants to resize.
      This comes as a loading speed-up aid, as most of users need to resample anyway.
      -program status (loading, processing, displaying, etc) is displayed now in the status bar
      -fixed a bug when images with a BPP other than 1,8, 24 and 32 cannot be rotated
      -small display speedups after rotate, flip. Image loading speed-up for BPP smaller than 24
      -fixes for paste from clipboard
      -metadata is now always kept
      -default resample filter is now Catmull Rom (very good results and decent speed)

      Download from RIOT website: http://luci.criosweb.ro/riot/

      You can also test the first release of the Lite plugin that will become an IV plugin. I've compiled a sample application that will let you test the plugin.
      The method used within IV will be Load from DIB.
      Download it from here: http://www.criosweb.ro/software/Riot_Lite.rar

      PS: Iv does not keep transparency at all. You have to choose it again.
      It does not keep it even on the same file with no modifications
      RIOT developer
      visit the Radical Image Optimization Tool website

      Comment


        #63
        Metadata greyed out

        Hi,

        I just downloaded both the full dll and stand alone versions of RIOT and in both cases, the metadata options are greyed out (and ticked) when I open a jpeg. Is there something I'm missing or doing wrong? Being able to adjust for web without going into Photoshop would be very usefull, but I need the ICC profiles retained. TIA

        Comment


          #64
          Try this:
          -Open a JPEG picture with embedded ICC profile using the program.
          -if ICC checkbox is disabled it means no ICC profile exists.
          -if not disabled you may choose to keep or remove the ICC profile
          RIOT developer
          visit the Radical Image Optimization Tool website

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