To apply both a threshold effect and leave color effects, similar to the Sin City movie, you can follow these steps using image editing software such as Adobe Photoshop or GIMP:
- Open your image in the image editing software.
- Duplicate the image layer. This will allow you to apply different effects to each layer independently.
- On the top layer, apply a threshold adjustment. In Photoshop, go to Image > Adjustments > Threshold. Drag the threshold slider to adjust the black and white cutoff point until you achieve the desired effect. This will convert the image to black and white.
- On the bottom layer, you will retain the color information. Make sure this layer is visible and positioned below the threshold layer.
- Adjust the opacity of the top threshold layer to blend the black and white effect with the colored layer below. You can experiment with different opacity values until you achieve the desired look. Usually, a low opacity value works well.
- If needed, you can further enhance the black and white effect by adjusting the contrast, brightness, or adding any other desired effects to the top threshold layer.