Something relative to image processing

Image formats

Image optimization

JPEG optimization:

mozjpeg binaries

# apt-get install cmake nasm
$ git clone https://github.com/mozilla/mozjpeg.git
$ cd mozjpeg
$ cmake .
$ make all install

Tools for JPEG optimization, jpegoptim vs jpegtran vs mozjpeg

None of the modern browsers support arithmetic-encoded JPEGs, see Firefox does not show arithmetic coded JPEGs.

PNG optimization:

Нейронная сеть как предиктор для кодирования изображений формата PNG
A guide to PNG optimization
- optipng -o7 $file && advpng -z -4 $file

Project	Debian packages	Comments
pingo¹⁾
pmt
pngquant	site
optipng	site	Lossy compression of PNG images
AdvanceCOMP	site	Takes advantage of 7-Zip and Zopfli DEFLATE encoders which are 5-10% more effective that zlib
PNG lossy averaging filter		Optimized lossy PNG is still a bit larger than lossy JPEG-XR/WebP/JPEG-2K, but unlike these formats it's supported by all browsers

Comparison:

Performance of libjpeg-turbo

Software

PicMonkey – free online image editing service

Panorama software

Image Composite Editor
Hugin – Panorama photo stitcher

Questions answered

How to open Nikon NEC files with PhotoShop?

You need to install Adobe Camera Raw and DNG Converter. The latest version for PhotoShop CS4 was DNG Converter v5.7. In order to learn the version of DNG Converter you need check the list of supported cameras here.

How to enable thumbnail generation for `.psd` files?

Check here.

How to convert PDF to the series of JPEG files?

One can use ImageMagic ''convert'' utility (or one from GraphicsMagic) for that (see Convert multipage PDF to PNG and back):

convert in.pdf -compress jpeg -quality 90 -density 600x600 +adjoin -scene 1 out-%d.jpg²⁾

but it generates low resolution images. Alternatively use Ghostscript (see Using Ghostscript to convert multi-page PDF into single JPG and Converting multi-page PDFs to several JPGs using ImageMagick and/or GhostScript):

gswin32c.exe -dBATCH -dNOPAUSE -dSAFER -sDEVICE=jpeg -dJPEGQ=95 -r600x600 -sOutputFile=out-%03d.jpg in.pdf³⁾

¹⁾ Former ScriptPNG

²⁾ , ³⁾ One need to double the percentage % when using in batch file