Gradient Map Tutorial
From 
to 
, and other stories.
I thought I'd write up some ideas on a facility offered in Photoshop which doesn't seem to be getting much attention at the moment: the Gradient Map. I expect that other graphics programs also offer this (unlike the elusive Selective Color), but if you aren't using Photoshop, you will have to seek out for yourselves the details of where to find it and what commands to use. My version of the program is PS CS, on a Mac.
Oh - I get a bit chatty, so this is quite long. Beginner-friendly, I hope. Quite a few images, too.
The way I'm accustomed to using Gradient Maps (etc) is in Adjustment Layer form - this means extra flexibility. So, I recommend that you don't use the Image menu to implement your GM (though you could, via Image > Adjustment > Gradient Map), as that has a 'global' effect and is not readily adjustable. If you're using Photoshop, you'll find your Gradient Maps (and other Adjustment Layers) most handily by using the little icon at the bottom of your Layers Palette. There's a tiny circle, half black, half white, which gives you a drop-down menu for Adjustment Layers. The Gradient Map is near the bottom. You can also reach this option via Layer > New Adjustment Layer > Gradient Map, but the thing on the bottom of the Layers palette is quicker and handier, I find.
Now for the interesting part: what can you do with a Gradient Map?
Perhaps the most obvious use is to change a colour picture to black and white.
Of course, you can change a colour image to b/w by changing it from RGB to Grayscale mode (Image > Mode > Grayscale). (see 1a, 1b) It's simple, but very flat. The Gradient Map gives you more options, and besides, will keep your image in RGB, so that you can add colour later, and also, use all the Adjustment Layer variations (some of which are not available in Grayscale).
So. The most obvious thing to do is start with your Foreground Color set to black, and your Background Color set to white. (The Foreground Color maps to the dark parts of the image, the Background to the pale.) Then, select the Gradient Map option from the drop-down menu.
You will get a small screen with a colour bar that graduates from your Foreground to your Background colours, left to right. (If they are the wrong way round, click Reverse.) You can go ahead and click OK at this point. Or, if you wish, adjust the gradient that will be applied. Click on that colour bar, and you'll get a Gradient Editor screen. There's another colour bar, with four pointers (like stubby little pencils), which you can adjust to vary the effect of your Gradient Map. Have a go. You can also move the tiny diamond to left or right, which again will adjust the image (the mid-point, indeed). Here, I've played around a little. (see 1c)
Of course, you don't have to do the messing about in the Gradient Editor. I'm pretty happy with the way the default Gradient Map image came out, but tweaked it a bit using a Levels layer instead. Levels can be found on the same drop down menu as Gradient Map. Essentially, using this adjusts the ratios of dark and light in the image. Move the LH pointer towards the right, and the image gets darker. Mover the RH pointer leftwards, and there's more light. The middle pointer adjusts the mid-range and again, moving right makes it darker, moving left makes it lighter. No doubt there is an elegant technical explanation, but the easiest way to understand what happens is to have a go, and see what you get. It's up to you whether you feel that's going to help with your particular image. If you want a simple b/w image for your icon, you may well want to adjust the Levels, and maybe the Brightness/Contrast too. (see 1d)
You'll have realised by now that you don't have to go black/white. You can select any colours on your Tools palette. Or, when you've got to the Gradient Editor screen, you can pick one of the other gradients and use that, which offers new and strange kinds of fun when you consider the multicoloured gradients available!
Just for fun, here's one that uses a vivid blue/red/green gradient from the Photoshop defaults. Playing around with the blending modes at this point brings up some interesting results.
Well. Now, how about trying some other colouring with Gradient Maps? It can be fun, and is well worth playing around with to see what serendipity shows you.
Here, I started with a base that has fairly coherent colour content. This one is basically yellows and reds, nothing blue or green. (see 2a)
I usually start on an icon by getting the base to look a bit nicer, so:
duplicate layer, multiply 100%
duplicate layer, screen
duplicate layer, soft light 100%, desaturate (select the layer, Image > Adjustments > Desaturate)
Now, he's a little more clearly defined (see 2b), and being as how I love the Chris, I'd be quite happy to leave it there... but I played around a bit more.
So, the Gradient map. It helps to pick something out from the tones in the picture, so I selected [Background color] the yellow of the background and [Foreground color] the dark red from the shadowed area of T-shirt. Then, because I am perverse that way, went a little paler with the yellow and a little browner with the dark red. (see 2c, 2d)
While you're here, try checking out what happens with the different blending modes. Soft Light just allows the Gradient Map to emphasize your picture a little bit, whereas Color gives it a different hue. See what you like. You may be happy with it now.
Or, you could go on a little, as I did. Create an amalgamated layer (New layer, then Cmd+alt+Shift+E on my Mac, PC users probably need a Ctrl in there somewhere) and put it on Soft Light, to sharpen things up a bit.
The finishing touches are easy.
New layer. Select a soft brush, and on your Brush palette, give the brush Wet Edges and deselect such unnecessaries as Color Dynamics and Other Dynamics. I started with a largeish brush, about a 35, dabbed on a few blobs using the pale yellow from the Gradient Map, and set the layer to Overlay, which gave a pleasing red glow here and there. Then another fresh layer, and a rather smaller brush (just reduce the size of the brush on the sliding scale of the Brush palette, rather than selecting a new brush and going through it all again), and same deal. Then another fresh layer with small brush, this time on Hard Light, which produced the pale yellow blobs.
Thus the finished icon (see 2d).
You can also go for something a bit more extreme. I started with a fairly simple base and instead of something natural-ish, went for a rich purple/bright yellow gradient. (see 3a, 3b, 3c)
There's an amalgamated layer here, set to Screen at 19%. Then, I added a simple Gradient using the same purple (select the Foreground Color you want, then use the Gradient option in the drop-down menu of Adjustment Layers, the one where you found the Gradient Maps), in the lower LH corner, but set it to Vivid Light, and found that pink edges miraculously appeared. (see 3d) As I wasn't out for a natural kind of look, that was fine with me. Added a simple Gradient in the yellow, upper RH corner, set to Soft Light at 68%, just to highlight his face a little more. The text picks up the bright pink colour that just happened along. Finally, I added a Levels adjustment layer, on which I moved the light point to the left a bit, to get a greater contrast.
It's probably not for everyday, but it's fun for a change. (see 3e)
But you don't have to change the basic colours of your picture - you can use a Gradient Map for emphasis, to enhance what is there.
Take this nice little JC piccie. (nb if this part of the tutorial looks familiar, I did produce a tut for the icon some months ago. Sorry about the repetition) I did the multiply/screen/desaturated soft light layers as described for the Chris icon (see 4b), and added a Gradient Map going from a smoky mid-range blue to a light peachy pink (4c). The result was this (4d). Admittedly, it's kinda cheating, as this man is about as pretty as it's possible to be, but I'm quite pleased with the way he's shown off here. The finished icon uses a pretty border (by
dj43) with a gradient overlaid, and a smidgin of tiny text.
And finally, another example of how you can use the Gradient Map to emphasize and enhance what is there.
Here's a base, needs a bit more definition. Ahem. (5a) Apply a b/w Gradient Map, set it to Soft Light, and suddenly, there's more definition. Nice. Then I adjusted the Levels a bit, moving the Light pointer left (see 5b).
But you could also use the Gradient Map to adjust the colouring: this one goes from dark, slightly purplish blue to a very pale mauve-y blue. (see 5c, 5d)
To finish off, I amalgamated the lot into a new layer and duplicated this. The uppermost was set to Soft Light, I added a Gaussian Blur of about 1.3, then masked off the area in the top left where the pretty background shows. I then masked off Justin's face and body in the lower amalgamated layer, sharpened the layer and set to Color Burn at around 50%. Finally, added a Gradient from the lower RH corner, using the pale blue, and put it under the topmost Soft Light layer. (5e) Purty, huh?
I hope this has given you some ideas on how you can play with Gradient Maps, and a few of the things that may result. Have fun!
If anyone can comment with information I've forgotten or didn't know, I'll be very pleased to learn more.
to , and other stories.I thought I'd write up some ideas on a facility offered in Photoshop which doesn't seem to be getting much attention at the moment: the Gradient Map. I expect that other graphics programs also offer this (unlike the elusive Selective Color), but if you aren't using Photoshop, you will have to seek out for yourselves the details of where to find it and what commands to use. My version of the program is PS CS, on a Mac.
Oh - I get a bit chatty, so this is quite long. Beginner-friendly, I hope. Quite a few images, too.
The way I'm accustomed to using Gradient Maps (etc) is in Adjustment Layer form - this means extra flexibility. So, I recommend that you don't use the Image menu to implement your GM (though you could, via Image > Adjustment > Gradient Map), as that has a 'global' effect and is not readily adjustable. If you're using Photoshop, you'll find your Gradient Maps (and other Adjustment Layers) most handily by using the little icon at the bottom of your Layers Palette. There's a tiny circle, half black, half white, which gives you a drop-down menu for Adjustment Layers. The Gradient Map is near the bottom. You can also reach this option via Layer > New Adjustment Layer > Gradient Map, but the thing on the bottom of the Layers palette is quicker and handier, I find.
Now for the interesting part: what can you do with a Gradient Map?
Perhaps the most obvious use is to change a colour picture to black and white.
Of course, you can change a colour image to b/w by changing it from RGB to Grayscale mode (Image > Mode > Grayscale). (see 1a, 1b) It's simple, but very flat. The Gradient Map gives you more options, and besides, will keep your image in RGB, so that you can add colour later, and also, use all the Adjustment Layer variations (some of which are not available in Grayscale).
So. The most obvious thing to do is start with your Foreground Color set to black, and your Background Color set to white. (The Foreground Color maps to the dark parts of the image, the Background to the pale.) Then, select the Gradient Map option from the drop-down menu.
You will get a small screen with a colour bar that graduates from your Foreground to your Background colours, left to right. (If they are the wrong way round, click Reverse.) You can go ahead and click OK at this point. Or, if you wish, adjust the gradient that will be applied. Click on that colour bar, and you'll get a Gradient Editor screen. There's another colour bar, with four pointers (like stubby little pencils), which you can adjust to vary the effect of your Gradient Map. Have a go. You can also move the tiny diamond to left or right, which again will adjust the image (the mid-point, indeed). Here, I've played around a little. (see 1c)
Of course, you don't have to do the messing about in the Gradient Editor. I'm pretty happy with the way the default Gradient Map image came out, but tweaked it a bit using a Levels layer instead. Levels can be found on the same drop down menu as Gradient Map. Essentially, using this adjusts the ratios of dark and light in the image. Move the LH pointer towards the right, and the image gets darker. Mover the RH pointer leftwards, and there's more light. The middle pointer adjusts the mid-range and again, moving right makes it darker, moving left makes it lighter. No doubt there is an elegant technical explanation, but the easiest way to understand what happens is to have a go, and see what you get. It's up to you whether you feel that's going to help with your particular image. If you want a simple b/w image for your icon, you may well want to adjust the Levels, and maybe the Brightness/Contrast too. (see 1d)
You'll have realised by now that you don't have to go black/white. You can select any colours on your Tools palette. Or, when you've got to the Gradient Editor screen, you can pick one of the other gradients and use that, which offers new and strange kinds of fun when you consider the multicoloured gradients available!
Just for fun, here's one that uses a vivid blue/red/green gradient from the Photoshop defaults. Playing around with the blending modes at this point brings up some interesting results.
Well. Now, how about trying some other colouring with Gradient Maps? It can be fun, and is well worth playing around with to see what serendipity shows you.
Here, I started with a base that has fairly coherent colour content. This one is basically yellows and reds, nothing blue or green. (see 2a)
I usually start on an icon by getting the base to look a bit nicer, so:
duplicate layer, multiply 100%
duplicate layer, screen
duplicate layer, soft light 100%, desaturate (select the layer, Image > Adjustments > Desaturate)
Now, he's a little more clearly defined (see 2b), and being as how I love the Chris, I'd be quite happy to leave it there... but I played around a bit more.
So, the Gradient map. It helps to pick something out from the tones in the picture, so I selected [Background color] the yellow of the background and [Foreground color] the dark red from the shadowed area of T-shirt. Then, because I am perverse that way, went a little paler with the yellow and a little browner with the dark red. (see 2c, 2d)
While you're here, try checking out what happens with the different blending modes. Soft Light just allows the Gradient Map to emphasize your picture a little bit, whereas Color gives it a different hue. See what you like. You may be happy with it now.
Or, you could go on a little, as I did. Create an amalgamated layer (New layer, then Cmd+alt+Shift+E on my Mac, PC users probably need a Ctrl in there somewhere) and put it on Soft Light, to sharpen things up a bit.
The finishing touches are easy.
New layer. Select a soft brush, and on your Brush palette, give the brush Wet Edges and deselect such unnecessaries as Color Dynamics and Other Dynamics. I started with a largeish brush, about a 35, dabbed on a few blobs using the pale yellow from the Gradient Map, and set the layer to Overlay, which gave a pleasing red glow here and there. Then another fresh layer, and a rather smaller brush (just reduce the size of the brush on the sliding scale of the Brush palette, rather than selecting a new brush and going through it all again), and same deal. Then another fresh layer with small brush, this time on Hard Light, which produced the pale yellow blobs.
Thus the finished icon (see 2d).
You can also go for something a bit more extreme. I started with a fairly simple base and instead of something natural-ish, went for a rich purple/bright yellow gradient. (see 3a, 3b, 3c)
There's an amalgamated layer here, set to Screen at 19%. Then, I added a simple Gradient using the same purple (select the Foreground Color you want, then use the Gradient option in the drop-down menu of Adjustment Layers, the one where you found the Gradient Maps), in the lower LH corner, but set it to Vivid Light, and found that pink edges miraculously appeared. (see 3d) As I wasn't out for a natural kind of look, that was fine with me. Added a simple Gradient in the yellow, upper RH corner, set to Soft Light at 68%, just to highlight his face a little more. The text picks up the bright pink colour that just happened along. Finally, I added a Levels adjustment layer, on which I moved the light point to the left a bit, to get a greater contrast.
It's probably not for everyday, but it's fun for a change. (see 3e)
But you don't have to change the basic colours of your picture - you can use a Gradient Map for emphasis, to enhance what is there.
Take this nice little JC piccie. (nb if this part of the tutorial looks familiar, I did produce a tut for the icon some months ago. Sorry about the repetition) I did the multiply/screen/desaturated soft light layers as described for the Chris icon (see 4b), and added a Gradient Map going from a smoky mid-range blue to a light peachy pink (4c). The result was this (4d). Admittedly, it's kinda cheating, as this man is about as pretty as it's possible to be, but I'm quite pleased with the way he's shown off here. The finished icon uses a pretty border (by
dj43) with a gradient overlaid, and a smidgin of tiny text. And finally, another example of how you can use the Gradient Map to emphasize and enhance what is there.
Here's a base, needs a bit more definition. Ahem. (5a) Apply a b/w Gradient Map, set it to Soft Light, and suddenly, there's more definition. Nice. Then I adjusted the Levels a bit, moving the Light pointer left (see 5b).
But you could also use the Gradient Map to adjust the colouring: this one goes from dark, slightly purplish blue to a very pale mauve-y blue. (see 5c, 5d)
To finish off, I amalgamated the lot into a new layer and duplicated this. The uppermost was set to Soft Light, I added a Gaussian Blur of about 1.3, then masked off the area in the top left where the pretty background shows. I then masked off Justin's face and body in the lower amalgamated layer, sharpened the layer and set to Color Burn at around 50%. Finally, added a Gradient from the lower RH corner, using the pale blue, and put it under the topmost Soft Light layer. (5e) Purty, huh?
I hope this has given you some ideas on how you can play with Gradient Maps, and a few of the things that may result. Have fun!
If anyone can comment with information I've forgotten or didn't know, I'll be very pleased to learn more.