Change Jpeg into progressive Jpeg Image

You can do that with ImageMagick which is installed on most Linux distros and is available for OSX and Windows.

Make a copy before experimenting on a small batch of images!

You can do a whole directory full of JPEGs like this:

mogrify -interlace plane *.jpg

Or, if you want to do one at a time:

convert input.jpg -interlace plane output.jpg

Or, if you want to do a whole directory and every subdirectory on Linux/OSX:

find . -iname \*.jpg -exec convert {} -interlace plane {} \;

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Or, you can use GNU Parallel on Linux/OSX if you want to get the job done faster. That goes like this:

parallel -X mogrify -interlace plane ::: *.jpg

If you want the output in a directory called "progressive", use:

mkdir progressive
parallel -X mogrify -path progressive -interlace plane ::: *.jpg

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You can also do it with jpegtran which is miles easier to install:

jpegtran -copy none -progressive input.jpg output.jpg

Windows user here - I like to use a tool called irfanview which I have been using over 10 years now, it's a 3MB freeware and can do many sorts of (batch) modifications on images, some in lossless quality. powerful stuff.

I also use & recommend xnview which is available for MAC also and also has a command-line tool.

Simply view the JPEG you wish to convert and choose "save as" from the top left "file" menu and save using "progressive".