Photo Editing with Free Software, GIMP

"Milk and Cookies" by Debra Keirce
I am often asked what software I use to edit photos of my paintings, so I thought I'd write a blog post showing what I do. There are so many great ways to accomplish this, but I have been using GIMP, a free software I downloaded for the first time about ten years ago. Since then, I've purchased versions of Photoshop and experimented with other programs, but I keep going back to GIMP. I'm just familiar enough with it to be dangerous. But I seem to be able to do all the things my friends who pay hundreds of dollars do with other software programs.
Also, if you have any question about how to do anything at all in GIMP, do a google search. With the word GIMP and your question in the search bar, I could almost guarantee you will always find the answer you need. There's just THAT much information on GIMP on the internet. YouTube videos, chat rooms, the GIMP tutorials... I have yet to ask a question and not find the answer. This is important for me, because I am always full of questions.
Here is what I do with GIMP each time I want to photograph my artwork:

I'll write another post about my Canon Rebel camera and taking photos, but notice that for rectangular pieces, I photograph them sideways for the least distortion and so I can grab the most pixels. Once you download GIMP to your computer, drag the photo you want to edit over to the GIMP icon to open it in GIMP.

To rotate the image, go to the bar at the top of your computer screen. See the "Tools" tab? Click on it. Where it drops down to "Transform" click on that. See "Rotate"? Click there too. Now. There is a small screen that pops up and the highlighted place is where you enter the degree of rotation. In this case, I enter 90. I hit return, and viola. My image is upright.
Please note that this is a really useful tool, because sometimes you want to rotate an image just 2 or 3 or 30 degrees. You can do this. To rotate it in the counterclockwise direction, just insert a minus sign (dash) before the number. For example, -90. You can even use fractions if you want it to rotate, say 90.23 degrees. I have not found another free photo editing software that allows you this fine tuning in rotation. It's awesome!
After you rotate the image, you may need to adjust the size you are viewing in order to continue, depending on your computer monitor. This is easy. Just go to the bar below the image where you can choose to view it in inches, pixels, mm, etc. See that number? Change it to something bigger or smaller until the image is the size you want it to be for viewing. This doesn't change the size of your saved image - just the size it appears on your monitor.
If you do not see your whole image after rotating and resizing, you may need to go to the "Image" tab at the top of your screen. See the drop down option "Fit Canvas to Layers"? Click that and you are good to go.

Okay - It's subtle, but see what I did here? I squared up the image so it is now a rectangle instead of a trapezoid. It now appears as though I am looking at it straight on. It's often useful to intentionally photograph your work at an angle so you can avoid glare. Squaring it back up to a rectangle is easy with GIMP.
Do this. Go to the "Tools" tab at the top of your screen. Click on the drop down option "Transform." Then click on the drop down option "Perspective." A grid appears to help you see how NOT square your image is. I have found that it is most successful if you correct your image by making it smaller, instead of making it bigger. So, grab (i.e. click and drag) one of the four corners and move it toward the center of the image until you have lined up the vertical and horizontal edges of your rectangle. After you click and drag, wait for a few seconds before you release your click. When the image adjusts to where you have your pointer, then you can let go of the click.
Do this for all 4 corners and hit the "Transform" blue button on the small "Perspective" menu that popped up when you chose the perspective option. After the image adjusts, click on it so the grid pops up again. Now you can see how close to a true rectangle you are. Repeat the steps above if you need to adjust it further.

On to the cropping. Go to - you guessed it! - the "Tools" tab. Choose "Transform" in the drop down menu. Choose "Crop" in the drop down options. Click and drag to choose the cropping and hit return. You're there!

At this point, I typically feel like I need to adjust the brightness and contrast on my paintings, to get the image to match what it looks like in real life. This is tricky, I know, because different monitors show different color and brightness variations. All I can do is to make it look good on my computer, so right or wrong, that's what I shoot for. I have learned to stay away from adjusting colors. I only fiddle with the brightness and contrast. Here's how.
Go to the "Colors" tab at the top of your GIMP screen. Choose "Brightness and Contrast" in the drop down menu. Make your adjustments and hit "OK" in the pop up window for that tool.
There are a lot of really cool editing tools you can experiment with. Under the "Tools" tab at the top of your screen, choose "New Toolbox" and a toolbox will show up. If you hover over each of the icons in it, the title of each tool will pop up. I found the best way to learn about them was to experiment. I often use the "color picker" and "paintbrush" tools to choose a color and then paint over specks of dust on frames. You can also use these tools to adjust photo references. But that's a topic for another blog post.

Now you can go to "Tools" and "Transform" and "Crop" again to crop out the frame. Hit return, and you are done!
At any step along the way, you can save your image. To do this, go to the "FILE" tab at the top of your screen. Click on "Export As" in the drop down menu. Here you have choices. Choose what to name your file, where on your computer you want to save it to, and if you click on the arrow next to "Select File Type (By Extension)" in the pop up window for exporting, you have the option to save your file as a TIFF file. I have never done this. Every publication I have been in asks for JPG files. In the last century, TIFF files were the norm for print publication files, because they are less corrupted over continued opening and closing. So far, I've sold each painting BEFORE anybody has asked for a TIFF file. But, it's there if you think you need it. Hit the blue "Export" button.
A smaller pop up window appears and now your can choose the quality of your image. This amounts to the number of pixels. I save 100% at this point. You can also make some advanced option changes here. Hit export and you are done.
Another thing you can do, is to scale your image. This is a really useful tool, as competitions and publications often want an image to be a specific number of pixels or inches. To do this, click on the "Image" tab at the top of your GIMP screen. Then choose "Scale Image" in the drop down menu. See the little pop up window where you can choose units of pixels, picas (what the heck is a pica?), millimeters, feet, yards, etc? Choose. You can also choose resolution. 72 Pixels/Inch is great for the internet. We call this low resolution. When someone asks for high resolution photos, you can change this number to 300. Note that when you do this, the image size will decrease. Whatever your resolution is, you only have a set number of pixels to work with. So you can choose to have a huge image with fewer pixels per square inch, or a very crisp image with lots of pixels per square inch, but in a reduced size. The human eye cannot distinguish higher than a few hundred pixels/inch, so anything above 300 pixels per inch resolution is lost on humans. There are machines out there that sometimes appreciate it though...hi res printers and such.
Also note that when you adjust the image size and quality, there is that little link next to the numbers. Click on that link icon to be sure the height changes when you alter the width, and the x resolution (horizontal) alterations result in y resolution (vertical) changes. If you make changes without linking these attributes, you can get some wacky stuff going on.
Below, is a 300 pixel/square inch image of the same 72 pixel/square inch image shown above. If you zoom in on your computer screen, you can see the difference. If your eyes are like mine, they look pretty much the same unmagnified. So, like I said, 72 ppi (pixels per inch) is fine on the internet.

I hope that helps, and I hope you are now more able to share your beautiful art - and any other images you care to share - with the world. The earth gets prettier every time we share a beautiful piece of art. Thank you for reading!!
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