Satellite Image Editting Mini Tutorial

Introduction

This tutorial will teach you how to quickly and easily remove lighting information from photographic texture sources. The raison d'etre for this was to help someone with their island texture and so it's written with satellite imagery as the example. These techniques can be applied to almost any appropriate photo texture source, though. It is geared towards novice photoshop users.

Getting Started

Alright. To use this tutorial, you're going to need some version of Photoshop. I know these techniques work in Photoshop cs3 and cs2. I'm not sure at what version they introduced these tools.

I'm going to proceed as if you have very little to no photoshop experience, so bare with me.

So you have a raw satellite image with shadows from the angle of the sun at the time the photo was taken. This isn't going to jive with your island because the photos may or may not correspond 100% to the topography of your island, and certainly will not correspond to the angle of arma's sun 100% of the time, if at all.

Using the following technique, I was able to get this photograph to a reasonable state in ten minutes. It's very fast and easy. My texture still requires a bit of attention and the image is small, but I think you can agree that it's a fairly good result for ten minutes!

[ATTACH=CONFIG]157[/ATTACH] [ATTACH=CONFIG]158[/ATTACH]

If you want to follow along with this image, you can find that image here:

http://freegeographytools.com/wp-cont....umb.jpg

Removing the Lighting

So, here we go.

Open up your photo texture in photoshop, and find the Shadows/Highlights tool under Image\Adjustments\Shadow/Highlights. For this picture I used values that were something like (I don't completely remember):

Shadows

Amount: 75

Tonal Width: 60

Radius: 0

Highlights

Amount: 41

Tonal Width: 5

Radius: 0

Adjustments

Colour Correction: 35

Midtone Contrast: 39

If you don't see all of these options, you have to explode the dialogue by ticking 'show more options'. You'll notice that the colour values of the photo will now be squished to the centre of the range with the exception of whatever was black in the photo (you can see this in the histogram if you view the levels). The deep shadows will remain and we will require other methods to get rid of them.

Cleaning Up

Let me introduce you to the healing brush tool and the clone stamp tool. To do this particular photo, I didn't use the clone stamp tool, but it offers you more control. On the tools palette, the healing brush icon looks like a band-aid and the clone stamp looks like a rubber stamp. They do basically the same thing, only with the clone stamp tool, you choose what area of the photo to sample from, and with the healing brush, the computer chooses. To get a better idea of what they do, just play around with them

To get rid of the black smears all over the image, use the healing brush with a fairly large brush (for this image I used 32 pixels, 100% sharpness) in very short strokes, and lead in from the edge of the shadow toward the centre. If it samples something you don't like, simply keep sampling over that spot or undo and try again.

After you're done, you'll find that you have an image that has fairly low contrast and probably more saturation than you need. Simply edit the hue/saturation of the image and adjust the levels of the image to finish. This is something I didn't do in my example. Getting rid of some colour saturation will help reduce some cartoonishness.

I hope this helps you adapt photographic reference to game art in general.

Regards,

Plaintiff1

Good tutorial, am using a lot of these techniques already, but it can be a real pain with megatextures that are 20480x20480 px.

Any tips on optimizing performance on PS?

Eh, that's cool Plaintiff1, it's nice to see some technique's in public

Good tutorial, am using a lot of these techniques already, but it can be a real pain with megatextures that are 20480x20480 px.

Any tips on optimizing performance on PS?

Opteryx, in Photochop CS3 under preferences, there is a "Performance" Menu that allows you to adjust the amount of ram you want to dedicate to PS, as well as an area for defining other "Scratch Disks" which can improve performance by caching the multiple levels of alteration you do to the image, on other disks.

In Photochop CS2 Under Preferences, "Memory & Image Cache" you can do the same as above, for RAM. Under "Plug-ins & Scratch Disks" you can also define other drives for scratch disks where Photchop will cache the multiple alterations to the image you are working on.

Don't forget to play with the "Cache Levels" to see how many levels are good for your working environment.

Eh, that's cool Plaintiff1, it's nice to see some technique's in public

Good tutorial, am using a lot of these techniques already, but it can be a real pain with megatextures that are 20480x20480 px.

Any tips on optimizing performance on PS?

Opteryx, in Photochop CS3 under preferences, there is a "Performance" Menu that allows you to adjust the amount of ram you want to dedicate to PS, as well as an area for defining other "Scratch Disks" which can improve performance by caching the multiple levels of alteration you do to the image, on other disks.

In Photochop CS2 Under Preferences, "Memory & Image Cache" you can do the same as above, for RAM. Under "Plug-ins & Scratch Disks" you can also define other drives for scratch disks where Photchop will cache the multiple alterations to the image you are working on.

Don't forget to play with the "Cache Levels" to see how many levels are good for your working environment.

Oh yeah, I've already done that, was hoping if anyone knew something beyond that.

Thanks for the tutorial Plaintiff1. Although I don't have any dealings with satellite imagery as I don't make islands (or at least, ahevn't attempted to do so yet), you've opened my eyes to a few nice features in Photoshop I hadn't had experience with previously.

Another consideration for performance is your choice of scratch disk. Typically, if both of your hdd's are the same rpm, the smaller of the two will be the faster one. Also, it's good to set up your scratch disk to be on the hard drive that photoshop isn't on, I think. In general, it's best to install your high performance demand programs on a hard disk that windows isn't on.

edit: oh, another thing I forgot to add. That highlight filter seems to add some orange to the colour palette of the image. To get back to the original colours (which, in this image, look a little suspect), you may need to adjust the colour levels using the hue adjustment or by editing the levels of each of the colour channels.

Typically, if both of your hdd's are the same rpm, the smaller of the two will be the faster one.

Afaik the bigger one is faster because the data density is bigger and therefore is faster to reach.

Typically, if both of your hdd's are the same rpm, the smaller of the two will be the faster one.

Afaik the bigger one is faster because the data density is bigger and therefore is faster to reach.

Yes, but also, it depends on the drive really.

Some older drives use more platters, while newest drives use higher density. The Hitachi 1TB drive uses five-200GB platters, while a Seagate uses four-250GB platters while Samsung uses three-334GB platters.

I have a 74GB WD Raptor 16MB cache, and two 150GB WD Raptors 16MB cache, all manage a sustained burst speed of at least 123MB's, so cache + RPM = win.

Also directly about Photoshop, from the Adobe Support Sections:

Quote[/b] ]TechNoteImprove performance in Photoshop CS2 on computers with more than 1 GB RAM

What's covered

About image tile size in Photoshop CS2

Activating the Bigger Tiles plug-in

Adobe Photoshop CS2 uses complex memory management procedures. On computers with 1 GB of RAM or more, you can optimize Photoshop to take advantage of the quantity of RAM in your system and manage memory more efficiently.

About image tile size in Photoshop CS2

When Photoshop processes image data, it divides the image into sections called tiles. By default, the maximum size of each tile is 132 KB of RAM.

You can activate the Bigger Tiles plug-in to increase the tile size. If you assign 261 MB to 1 GB of RAM to the Memory & Image Cache preference in Photoshop, the tile size increases to 260 KB. Likewise, if you assign more than 1 GB RAM, the tile size increases to 1 MB. Activating the plug-in reduces the overall amount of time Photoshop takes to process an image, especially on computers with more than 1 GB of RAM.

After you activate the Bigger Tiles plug-in, Photoshop takes longer to draw each tile and may appear to draw images on screen slower, especially large images or when applying some filters. However, the total time Photoshop needs to display the entire image is less because it has fewer tiles to draw.

Activating the Bigger Tiles plug-in

To enable the Bigger Tiles plug-in:

1. Quit Photoshop.

2. Locate the ~Bigger Tiles plug-in file:

-- Mac OS: Applications/Adobe Photoshop CS2/Plug-Ins/Adobe Photoshop Only/Extensions/Bigger Tiles

-- Windows: Program Files/Adobe/Adobe Photoshop CS2/Plug-Ins/Adobe Photoshop Only/Extensions/Bigger Tiles

3. Rename the file, removing the tilde (~) from the file name.

4. Start Photoshop.

A revised edition of this tutorial is now available from OFPEC.

http://www.ofpec.com/ed_depo....&cat=ad

Typically, if both of your hdd's are the same rpm, the smaller of the two will be the faster one.

Afaik the bigger one is faster because the data density is bigger and therefore is faster to reach.

Yeah, I had my head on backwards. The fact that I was trying to recall is that faster ones are usually smaller... not smaller ones are usually faster.

Ultimately, spindle speed affects data through-put the most. However, the faster the drive spins the less data that the platter can hold. The ratio isn't linear either, as the storage space is inversely proportional to the square of the platter velocity.

Basically, maximum storage for a conventional 4.25" HDD looks like this:

- 7200 RPM drives = 1TB

- 10,000 RPM drives = 150 GB

- 15,000 RPM drives = 12GB

This information isn't pertinent to the discussion of swap discs, though. Typically, the more expensive hdd is the faster one.