Convertion of Colour photo to Black and White

I am giving bellow different methods to convert a colour picture to black and white. I hope this will answer the questions posted to me. I am sure you are familiar with all these methods. I used the channel mixer option to convert the picture of the old ladies. Surely the levels were adjusted , have made some selective adjustments of the shadow and high light area, used the colour filter and have given some manual lighting.

Convert to gray scale mode

Selecting this option, discards all colour information and only leaves a gray channel. Which means you lose 2/3 of your image data.

Desaturate the image

This method does keep all the channels and data intact but renders a very low contrast black and white image.



Channel mixer

The best method of conversion. It allows you mix the red, blue and green channels varying colours etc… surely the window has a box called Monochrome which need to be selected. Note the final count of all the channels should be 100.

Gradient map method

Compared to all the other methods, this renders a black and white image with the most contrast.

Select the correct gradient first (Black and white gradient since you need a BK picture)

The gradient map gives you a lot of control over the conversion. If you click on the black and white gradient, another window opens in which you can see a black point on the left, a white point on the right and a gray point in the middle of the gradient. You can use these three points like in Levels to adjust the tonality of the image.

Best result in all the conversions depends on your ability to increase or decrease the highlight or shadow selectively and also the ability to identify the light sources and if need increase or decrease the light falling on the object. Make sure the histogram of your image is good.