Poor-man’s sepia conversion

Working for Pixagogo makes digital imagery my daily bread, and I fool around with images every now and then. I am, however, not a user of PhotoShop. I’ve never worked with it, I don’t own the software, nada. Keep that in mind while you continue reading this.

Recently, for my cousin’s filmfilostoverij blog, I converted some film snapshots into small thumbnails like the one on the right (from “Lucia y el sexo”). The program I use for conversion is IrfanView. Not the best program, not the most complete, but easy, stable and free. For the stuff I need to do, I find Gimp too complex.

What I did to the images was:

  1. crop a square part of it
  2. convert to grayscale
  3. resize to 400×400 px
  4. perform a median filter (value: 9)
  5. resize to 100×100 px
  6. Save as JPG

But then I wanted to have a ‘sepia‘ effect. Irfanview does not have it. I wanted it. So I began my quest.

I started with the ‘Enhance Colors’ function and added 64 ‘R’ and 16 ‘G’ to the B/W image, but that didn’t look real enough. What does sepia look like, anyway? I found two definitions, expressed in CMYK coordinates, that I converted to RGB with my CMYK-to-RGB converter hizmo (thanks to Wikipedia):

The color
1. definecolor{Sepia}{cmyk}{0,0.83,1,0.70} (from TexCeh)
#4D0D00 (77,13,0)
2. sepia cmyk(0%, 60%, 81%, 63%) (from december.com)
#5E2612 (94,38,18)
In ‘websafe‘ colors, this would be:
#551100 (84,17,0)

So let me show you how I proceeded, using an image of my tango teachers, Marisa y Oliver:

original image
  1. Convert to greyscale
  2. Enhance colors: 94-38-18 (#5E2612)

=> way too red!

  1. Convert to greyscale
  2. Enhance colors: 77-13-0 (#4D0D00)

=> color OK, but too light

  1. Convert to greyscale
  2. Enhance colors: 77-13-0 (#4D0D00)
  3. Add 50% contrast

=> looks great</dd>

    Compare this with the optional QuickSepia plugin

=> I like mine better


Voila, there it is, a simple poor-mans sepia, that can even be used in ‘batch convert’ (Irfanview).

Short CMYK/RGB explanation and Detailed CMYK/RGB explanation

[Listening to: “The Prettiest Thing” – Norah Jones – Feels Like Home]

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