29

I used ImageMagick on Ubuntu to resize those big pictures. convert -resize 10% source.jpg dest.jpg It took awhile, but worked with 1 GByte of RAM, the tool created a 4.7 Gbyte swap-like file for itself. More information is on AskUbuntu.


23

I think you're going about this the wrong way. If you have 2GB of images at 4-5MB each, that's somewhere between 400 and 500 images. That's way too many. Even your close friends probably don't want to wade through all of that. Instead, go through and pick out the very best 10%. Or 5% or even 1%. Take some care and write a meaningful caption for each one. An ...


17

If you've tried enlarging in Photoshop, the first thing is to experiment with the resampling algorithm (photoshop suggests bicubic smoother as the best for enlarging, but I have found it to be image dependent (if you have an image with a lot of edges vs a portrait or landscape). Rather than smoothing, blurring I would suggest using a denoise program next, ...


16

Bear with me for a second here for some background.... When you downsample a 4000×3000 image to 400×300, you are "discarding" 11.9 million of the 12 million pixels. This clearly reduces "image quality", depending on what exactly you mean by that term. If you go from 1000×750 to 400×300, you're reducing the area by about 6 times. Again, data is discarded, ...


13

I have found the free waifu2x very good for upsizing images. You can try an online demo. It uses "Deep Convolutional Neural Networks" to predict what the missing image data should be. It works better for line art, but is definitely acceptable for photos.


12

Photoshop's Batch command can do this. You would essentially 'record' yourself performing the crop etc once, then run the recording on all the files you want. If you want to automatically resize the smaller images you would have to do a little scripting. Irfanview also has a comprehensive image batch processor but might require a bit of experimentation to ...


12

You have to convert them to some other format, but that format doesn't have to be JPEG. For example, you could save the files as TIFF or PNG instead of JPEG. RAW files are data read more or less straight from the sensor, so it doesn't make sense to "resize" such files. You have to instead process them into a useable image format, which you can then ...


11

First of all you need to use a good resize algorithm for that case. Lanczos, or Photoshop's Bicucbic optimized for reduction. And then to make for better contrast around the letters you can use some output sharpening. Secondly, there is a minimum resolution you can use to render the fine letters. The book is a perfect example because of the different fonts ...


11

Any photo you're never going to use again is taking up "unnecessary" space, and frankly no matter what happens to image processing technologies in the future, you're probably not going to go back and reprocess some low quality photos from 10 years ago. On the other hand, disk space is cheap (unless you're Google, Amazon, etc). Very roughly, my SLR has a ...


10

ImageMagick let's you run commands in a windows command window. You need to be comfortable with creating Dos batch files. For an example see the last post in this discussion: http://www.imagemagick.org/discourse-server/viewtopic.php?f=1&t=21112 Relevant example from this forum post: @echo off cd C:\Users\user\Desktop\New\New folder convert *.jpg -...


9

Theoretically, most image formats could be downscaled progressively, without loading the entire image into memory, however I do not know any tools that really implement such feature, except for JPEG: it is special in that you can not only downscale without loading full resolution, but also downscale without decoding full resolution, thanks to the creative ...


9

Have a DOG sniff out blur in the photos. If you're going to be penalizing for digitally enlarged photos, you might as well penalize for out-of-focus photos too. The blurred edges and details in both cause the same bad experience for viewers, regardless of whether it is caused by a small original or poor focus. What you want to do is detect blur, which is an ...


8

As is often the case, "there is no free lunch". JPEG is the de-facto standard image format, and uses lossy compression. That means that to get smaller file sizes, you will lose image quality. The only question is how much you lose, and whether that loss is acceptable. That said, there are lossless compression techniques that are used by other formats (...


7

First I thought you wanted batch resize, which many programs can do. But then I realized you want to do a combination of resizing and cropping, and you want the computer to calculate how to best cut out 600x600 pixels from the image dynamically. It is because it is not a "one true solution" kind of task, as it is usually human judgement call, how to crop ...


7

So, in this particular case, I think you have some options not necessarily always available. That's because your photo is really almost the required resolution — just the wrong shape. It looks like the rule behind the recommended sizes you've given is simply 150 pixels per inch. That is, 20" × 150 pixels = 3000 pixels per inch, and in the other dimension, ...


7

You could use dcraw to convert the raw image data to a "raw" tiff file that only contains the raw image data. You do that by giving the command "dcraw -D filename". This will produce a tiff file without any demosaicing or scaling. Such a tiff file is then smaller than an ordinary tiff file because each pixel is then only either a "red", "green" or a "blue" ...


7

You can also try using Picture Resizer on Windows (I love this tool) You simply drag and drop the picture on this simple EXE It is especially useful if you have many pictures to convert as you can do many at a time. All the config is done through the naming of the EXE which is brilliant IMO I have never tried it with huge file though.


7

Use a copy of your file, do not resize your original photo. You can use this free program: http://www.gimp.org/ Using Gimp: Open your file. Use the rectangle select tool. (Define some initial dimensions to set the proportion you need) Move it, scale if from the corners to mantain the proportion and frame your image. Menu > Image > Crop to selection. Now ...


7

The "ImageOptim" tool pulls together a bunch of other things, and in the case of JPEG files, the relevant thing is the MozJPEG optimizing encoder. If you use this encoder and then resize and save with a different encoder, you will lose the benefit. Saving with the optimizer needs to be the last step. Also worth noting: if you're starting with a JPEG and ...


6

It depends. If you have sufficient pixels for the size you need, than all you need is to change the DPI. So lets say you have a 12 megapixel image (4000 x 3000 pixels) at 300 DPI, then changing the DPI to 100 will make it 3 times bigger. This will take the 10" tall image and make it 30". Should you judge that you do not have enough pixels, you need to ...


6

Every digital image has a specific size: the width and height in pixels. The amount of information depends on that. In digital image files, the number of pixels per inch is just a hint. It indicates a proportion that should be used for calculating the actual size of the image when printed. If you have an image of 1000x1000 pixels and you print it at 100ppi,...


6

Select the RAW photos, then do an Export. In the Export Location section, choose Export To: Same folder as original photo. Check the Add to This Catalog Checkbox. Select the file output options you want for the new images. Export the images. At this point the JPG's will be imported into the same folder, and your RAW files should still be selected, ...


5

Pixels per inch don't actually exist until the image is rendered onto some physical medium such as paper or the monitor on your computer. The device doing the rendering determines PPI and PPI determines how large the image will appear when rendered. Rendering your 4000x3000 on a device capable of producing 240 PPI would produce a 16.6"x12.5" physical image....


5

If you like programing, you can use Python (computer language) and an excellent library know has PIL to crop, re-size, plot histograms, get individual pixel vales, etc... on a programmatic level. Thus you can easily write a simple script to find all images in a folder and perform the operation. This code should do exactly what you want and should process a ...


5

Having done some research on the Adobe Lightroom help site I found this article on how to export to file. http://help.adobe.com/en_US/lightroom/using/WS75C39DDC-B701-4840-A703-0755A5C04878.html I believe the feature you are referencing to is to do with Enhanced DNG options Resolution reduction via export provides the ability to share lower resolution ...


5

To understand why you can't do this, it's helpful to understand how RAW works. A RAW doesn't actually contain colored pixels, it's a single channel ("gray scale") image representing alternating red blue and green pixels called a Bayer pattern. To actually get the "actual" pixels, you have to extrapolate from each of the pixels neighbors using a complex ...


5

Depends. If you just resized the image in Word, it probably only changed the display scaling and didn't actually resize the image. If you did actually resize the image, though, this is an operation which inherently discards data. Once that information is gone, there's no way to get it back, because there's no where to get it back from.


4

Summary of requirement: I have more then two gigabytes of travel photography. Each image takes up than 4 to 5 megabytes. How can I resize all images while retaining high image quality? Extra comment: Image compression and quality: For comment on matters related to image compression "quality", and terms such as "lossy compression", "lossy ...


4

Most cameras have an anti-aliasing filter that can both reduce observed detail and moire patterns, especially when the image is viewed at 100%. The practice I follow is to do all my toning and cropping at the image's original size and then size the image down to the size I need it to be and then apply a sharpening tool to the image, like Photoshop's "...


4

First, you should be aware that most wide screen laptops are not 16:9 - they are made with the screen shorter to reduce size and cost, for example, you said your monitor is 1600x700 - you don't need too much math to work out this is 16:7 and not 16:9. Now that we got that out of the way it's actually easy to make a picture into a desktop background: First, ...


Only top voted, non community-wiki answers of a minimum length are eligible