Up-scaling, upsizing or digitally increasing the size of a picture is perhaps less of a requirement than the opposite i.e. cropping. The basic nature of a photo makes any change in its natural dimensions an ill advised task. As any guy who has dabbled with graphic tools will tell you, enlarging a raster or bitmapped image from its natural size results in blurring and fuzziness. In general, a loss in quality. But sometimes, the discouraged becomes the required. Even if it’s a bad idea, here are just three reasons why we might want to do it,
- For converting a digital photo for an enlarged hard print.
- For flipping a photo from vertical to horizontal and stretching it.
- For making an obscure image area more clear.
And here’s a simple reason why we should not ““
Pixels are the smallest units of an image. The number of pixels in an image is called the resolution. Imagine an image composed of thousands of little squares or dots. Each little square (or pixel) has its own color information. Enlarging an image using any program means increasing the pixel size or separating the pixels and this results loss in image information and lowers quality.
Upsizing an image also means that the program needs to figure out how to compensate the increase in image area. At best, an image editing program approximates how to represent the extra information.
Image manipulation involves a lot of mathematical rules called algorithms.
For those interested in more background, a Google search gives a lot of info. For instance, here are a couple of resources ““
So casting aside the overtly theoretical stuff (important nonetheless!) let’s dive into two useful photo tips to resize images without too much of a drop in quality.
FIRST METHOD: The Re-sampling by 10% Technique
Here’s a brief but brisk way to digitally increase picture size. This old photo tip involves using an image editor to resample an image by gradual 10% increments. Photoshop easily handles this using the Image Size commands.
- Open your image in Photoshop. (Screenshots are of Photoshop CS2)
- Click on Image ““ Image Size from the menu. Alternatively, right click on the image title bar and select Image Size.
- Choose Bicubic Smoother in the Resample Image dropdown.
- In the Pixel Dimensions setting, use the dropdown to select Percent instead of Pixels. Make sure the little chain link is set”¦else check the Constrain Proportions setting.
- To resize the image by 10%, change the width/height to 110 from the earlier 100 percent. Click OK to resize the image by 10%.
- You can continue to resize by increments by 10% till an optimum size where you can see that the visual quality hasn’t degraded by much. To undo a previous action, click on Edit ““ Undo Image Size or use the History palette to select an earlier state.
The snapshot below shows a section of an image taken through five increments of 10%. From an initial size of 500 X 369 to an enlarged size of nearly 800 X 600.
If you need to resize images more often, creating a Photoshop Action which does the job automatically is always better.
- In the Actions palette, click on the New Action icon.
- Give it a descriptive name like Resize By 10. You can also assign a shortcut key from the Function Key dropdown. Click on Record and start following through the steps mentioned earlier (Step 2 to Step 5). The actions get recorded and can be replayed again and again with a click of the play button (or the function key) for any selected image.
- After each increment, visually assess the image quality. After a certain percentage, image loss with blurring will be perceptible.
The resize by resampling can be achieved by any good photo editor. If you do not have Photoshop, you can resize similarly with the free IrfanView. The commands and there location might differ, but the technique is nearly the same
If you don’t have an image editor close at hand, then there’s an online option too.
SECOND METHOD: The Reshade Method
The second photo tip is to "reshade." Reshade.com offers a standalone image enlargement software package for Windows. The photo enlarger though is a paid download. As an alternative there is an online image resizer which is free and does the job equally well. The free online service though limited offers some notable features”¦
- You can use it directly from your browser (via a URL or an upload).
- You can resize images for free to any standard monitor resolution (max 1920x1200px).
- You can zoom to 2X of your original image size i.e. maximum 200% of the original resolution.
- You can crop part of an image, remove noise and improve its quality.
- You can upload images without a login which imposes certain restrictions like your images won’t be stored (that’s good in a way!), only allowed 3 uploads a day and you won’t be able to crop an image.
Browse to a locally stored image or submit it through a URL. The Submit button takes you to the image resize settings (as shown in the screenshot). Along with the resize settings, Reshade gives you five image enhancements checkboxes to play with ““ Center crop, Stretch, Denoise, Smooth and Crop.
You can then proceed to download it to your computer or post it to forums or social networking sites with the links provided. Do keep in mind that if you intend to post it, then it’s better to login and keep it in your online account.
Enlarging an image from its native resolution is paid for by lower quality. The best advice that goes around is to take a picture with the highest resolution possible and then downsize it. But in situations which ask for image upsize, these two solutions can prove helpful.
Do you have a tried and tested method to resize an image? Do you have any photo tips of your own? Let us know”¦
Image Credit: Cartel Soviet