I will be referencing Photoshop CS4 in this tutorial but the same features should be found in CS5 and CS6 (let me know if this isn’t the case)
Before starting it’s a good idea to clean the glass of your scanner to remove any dust and dirt that may have accumulated since the last scan.
Depending on the size of your scanner you may need to scan multiple times to get all of your image in. Make sure when scanning to include a large overlap. If you have an A4 scanner and an A3 image scan the top middle and bottom of the image to give a good overlap. This will make stitching them together much easier.
If you do need to stitch images together Photoshop has an easy way to do this called “Photomerge”. To use this click File > Automate > Photomerge
Choose “Auto” from the list on the left then browse for the scanned files, click OK, then OK again. This will merge your files together.
Adjusting your canvas and image
You may need to crop your image to remove untidy edges. Use the “Crop” (Shortcut = C) tool to do this. Make sure you put the dimensions you want the crop to be in boxes above then click and drag a box around what you want to keep.
If you have had to use the photomerge feature then it’s a good idea to merge the layers together before you make any colour adjustments to the layers. To do this select all the layers then right click on one of them and choose “Merge layers” (Shortcut = cmd+E).
You may find that the colours of your scanned image aren’t quite the same as your original so you may need to do a bit of adjustment. You will find the colour adjustments in Image > Adjustments. This gives you a range of options on how to change the colours of an image. Below are a few of the more frequently used adjustments.
By moving the black, grey or white triangles you can make the dark areas of your image darker or the lighter areas lighter. I find this useful for line drawings as I can darken my lines and make the background lighter.
Curves does the same sort of thing as levels but in a more fluid way. I like to use curves to add a bit of punch into my illustrations by making the blacks a bit darker and the lights brighter.
Change the hue, saturation or contrast of an image. You can also make an image monochromatic with the “Colorize” tick box.
If you want to shift the overall colour of an image use the the colour balance adjustment.
Another way of working is to use “Adjustment Layers”. These are their own layers that affect layers beneath them. There are many advantages to using adjustment layers as well as a few disadvantages. First the good. Adjustment layers can affect all the layers beneath them or just the one directly below it. To make an adjustment layer and make it only affect the layer below it click on Layer > New Adjustment Layer then choose an adjustment. Or you can click Window > Adjustments to bring up the adjustments panel. After choosing an adjustment and making the required changes you will see that a new layer has been made in your layers panel. The default action to affect all layers so to change this go to the adjustments panel ad click the icon at the bottom that looks like a dark circle over a light circle.
Adjustment layers can be changed and re-changed without loosing any image quality, unlike adjusting the actual image layer. Adjustment layers just like any other layer can have it’s opacity changed, have masks added to it and change its visibility. You can also move adjustment layers into another composition. This is good if you want the same effect for a multiple images.
Now the bad. Adjustment layers add to the size of your Photoshop file leading to slower performance. If you have a fast computer with lots of RAM and a large hard drive then this shouldn’t be a problem. The other issue is when you start to use too many adjustment layers. If you have adjustments affecting adjustments then it can get a little complicated if you want to turn off some and not others. You’ll just learn when to use them and when not, and how many is too many. I personally always first opt for an adjustment layer, then if I need to I can merge the adjustment layer with an image layer to cut down on the amount of layers.
Saving for the Web
When you are happy with your image click File > Save for Web & Devices. Here you can choose the dimensions and format of the image.
For uploading to a website, the suggested settings are:
Size: 800px x …
This will give a small file size with no noticeable loss in clarity. You can see the new file size in the bottom left of the pane. These are my preferred settings but you will have to have find the best settings that suit you.
And that’s it! If you’ve done a lot to an image make sure you save it as .PSD file when your done just in case you need to come back to it to make any more tweeks.