New answers tagged rescaling
Theoretically, most image formats could be downscaled progressively, without loading the entire image into memory, however I do not know any tools that really implement such feature, except for JPEG: it is special in that you can not only downscale without loading full resolution, but also downscale without decoding full resolution, thanks to the creative ...
You can also try using Picture Resizer on Windows (I love this tool) You simply drag and drop the picture on this simple EXE It is especially useful if you have many pictures to convert as you can do many at a time. All the config is done through the naming of the EXE which is brilliant IMO I have never tried it with huge file though.
I used ImageMagick on Ubuntu to resize those big pictures. convert -resize 10% source.jpg dest.jpg It took awhile, but worked with 1 GByte of RAM, the tool created a 4.7 Gbyte swap-like file for itself. More information is on AskUbuntu.
To understand why you can't do this, it's helpful to understand how RAW works. A RAW doesn't actually contain colored pixels, it's a single channel ("gray scale") image representing alternating red blue and green pixels called a Bayer pattern. To actually get the "actual" pixels, you have to extrapolate from each of the pixels neighbors using a complex ...
You could use dcraw to convert the raw image data to a "raw" tiff file that only contains the raw image data. You do that by giving the command "dcraw -D filename". This will produce a tiff file without any demosaicing or scaling. Such a tiff file is then smaller than an ordinary tiff file because each pixel is then only either a "red", "green" or a "blue" ...
You have to convert them to some other format, but that format doesn't have to be JPEG. For example, you could save the files as TIFF or PNG instead of JPEG. RAW files are data read more or less straight from the sensor, so it doesn't make sense to "resize" such files. You have to instead process them into a useable image format, which you can then ...
Top 50 recent answers are included