Post by Derek L on May 1, 2007 17:39:44 GMT -6
Resizing multiple images
Q. I gave my parents a digital photo frame as a gift. I loaded a bunch of JPEGs on a memory card. Unfortunately, some of the photos are so large that they take a long time to load. The instructions say that the pictures should be 600x480 (or smaller) resolution. Is there a program I could use to convert images to a smaller size in a batch? I know JPEGs can be compressed.
A. Yes, many programs can resize batches of photos. First, let’s clear up the difference between photo size and compression. It confuses a lot of people. Understanding the difference will help you take better pictures. And when you edit or resize your photos, you’ll get better results.
Most cameras allow you to take photos in three (or more) sizes. The sizes vary depending on how many megapixels a camera has. For example, a 10.2-megapixel camera will take larger photos than a 6.1-megapixel camera.
A lot of attention is paid to megapixels when it comes to marketing cameras. Many people equate it with image quality. But megapixels simply dictate how big you can make a picture and get decent prints.
The more closely spaced pixels are, the smoother the image will look. If an image contains more megapixels, the more you can enlarge it.
Of course, the more megapixels, the larger the file size. Larger files cause photos to load more slowly in your picture frame.
Compression is different from photo size. Cameras usually have three levels of compression. The less compression used, the larger the file size. And, the better the prints will look.
Compression reduces the amount of data in a picture file. It doesn’t do this by reducing the number of pixels. Rather, it reduces the number of colors.
For example, you may have 100 different shades of blue in a picture. Compression will eliminate shades of blue that are similar to other shades. One level of compression may reduce the 100 shades to 80 shades. More compression may cut the number of shades in half.
Compression can make your photos look bad. Subtle transitions may become distinct bands of color.
The best way to reduce a picture’s file size is to resize the image. If that doesn’t work, then try a little compression. JPEGs are already compressed. So, don’t compress them further unless necessary.
You say the frame maker recommends photos that are 600x480 pixels. This isn’t a standard photo size. The recommended size probably is 640x480. You can make your photos this size without distortion.
Here are three programs that will resize batches of photos:
Fast Image Resizer, adionsoft.net/fastimageresize/
Fotosizer www.fotosizer.com/ and
Multiple Image Resizer .NET. www.multipleimageresizer.net/
They run on both Windows XP and Vista.
All three programs are easy to use. Some let you specify custom sizes. But, that isn’t a necessity. You need 640x480, a common size.
Of these programs, Multiple Image Resizer .NET may be the best. It’s also the most complicated. But you can use it to rotate and flip images. You can also change the compression of your images.
Make sure you don’t reverse height and width when you resize your photos. If you’re resizing a photo in landscape orientation (the horizontal edge is longer), use 640 as the width and 480 as the height. For photos taken in portrait orientation (the vertical edge is longer), use 480 as the width and 640 as the height.
If you don’t pay attention to this, your photos will be distorted. For example, your subjects will look short and fat. You can’t resize portrait- and landscape-oriented photos simultaneously.
These little complications can be confusing. But figuring them out is worthwhile.
Q. I gave my parents a digital photo frame as a gift. I loaded a bunch of JPEGs on a memory card. Unfortunately, some of the photos are so large that they take a long time to load. The instructions say that the pictures should be 600x480 (or smaller) resolution. Is there a program I could use to convert images to a smaller size in a batch? I know JPEGs can be compressed.
A. Yes, many programs can resize batches of photos. First, let’s clear up the difference between photo size and compression. It confuses a lot of people. Understanding the difference will help you take better pictures. And when you edit or resize your photos, you’ll get better results.
Most cameras allow you to take photos in three (or more) sizes. The sizes vary depending on how many megapixels a camera has. For example, a 10.2-megapixel camera will take larger photos than a 6.1-megapixel camera.
A lot of attention is paid to megapixels when it comes to marketing cameras. Many people equate it with image quality. But megapixels simply dictate how big you can make a picture and get decent prints.
The more closely spaced pixels are, the smoother the image will look. If an image contains more megapixels, the more you can enlarge it.
Of course, the more megapixels, the larger the file size. Larger files cause photos to load more slowly in your picture frame.
Compression is different from photo size. Cameras usually have three levels of compression. The less compression used, the larger the file size. And, the better the prints will look.
Compression reduces the amount of data in a picture file. It doesn’t do this by reducing the number of pixels. Rather, it reduces the number of colors.
For example, you may have 100 different shades of blue in a picture. Compression will eliminate shades of blue that are similar to other shades. One level of compression may reduce the 100 shades to 80 shades. More compression may cut the number of shades in half.
Compression can make your photos look bad. Subtle transitions may become distinct bands of color.
The best way to reduce a picture’s file size is to resize the image. If that doesn’t work, then try a little compression. JPEGs are already compressed. So, don’t compress them further unless necessary.
You say the frame maker recommends photos that are 600x480 pixels. This isn’t a standard photo size. The recommended size probably is 640x480. You can make your photos this size without distortion.
Here are three programs that will resize batches of photos:
Fast Image Resizer, adionsoft.net/fastimageresize/
Fotosizer www.fotosizer.com/ and
Multiple Image Resizer .NET. www.multipleimageresizer.net/
They run on both Windows XP and Vista.
All three programs are easy to use. Some let you specify custom sizes. But, that isn’t a necessity. You need 640x480, a common size.
Of these programs, Multiple Image Resizer .NET may be the best. It’s also the most complicated. But you can use it to rotate and flip images. You can also change the compression of your images.
Make sure you don’t reverse height and width when you resize your photos. If you’re resizing a photo in landscape orientation (the horizontal edge is longer), use 640 as the width and 480 as the height. For photos taken in portrait orientation (the vertical edge is longer), use 480 as the width and 640 as the height.
If you don’t pay attention to this, your photos will be distorted. For example, your subjects will look short and fat. You can’t resize portrait- and landscape-oriented photos simultaneously.
These little complications can be confusing. But figuring them out is worthwhile.