Finding images for graphic design can be daunting, if the source images you are given have not been maintained well—or you have to find your own.
This is a brief guide on extracting original quality images from common document formats: web page, PDF, Word, PowerPoint, and EPUB.
The last section is on how to find better versions using Google Image search.
You should consider screenshots to be your last resort, because that will a) reduce the image quality and b) destroy the image's resolution information.
In all instructions below, all images should be saved neatly in a folder. You will have to dig through and delete extraneous files.
Open the website in Chrome, and scroll through the entire article so that the all images are loaded visible.
File → Save Page As...
Select Webpage, Complete, and save.
Scrolling is important because hidden images may not be saved. This will work for most websites but not all, depending on how the images are displayed.
Note: Some graphic elements may not be images. In this case, you need to make a screenshot.
If you have Photoshop (preferred method)
Open PDF in Photoshop
Select the images you want and click OK.
To select multiple images, either use the Shift key, or Cmd for macOS / Ctrl for Windows.
If you don't have Photoshop (lossy)
Go to https://smallpdf.com/pdf-to-jpg (Links to an external site.)Links to an external site. and upload your PDF
Select "Extract Images"
Download the .zip file
Note: images extracted this way will not be original quality. Photoshop is the best way to get images from PDFs.
Word / MS Office Documents
Open the document.
File → Save As... → Web Page (.htm) → Save
Rename the file from <filename>.epub to <filename>.zip. Ignore warnings.
Unzip the file.
For all other ebook or document formats without DRM (i.e. you need to authenticate to open the file), use an online converter to convert to one of the file formats above and follow relevant instructions.
Find higher-quality versions of an image
This won't always work, but it can be a huge help if your favorite image is too small to use in print.
Go to images.google.com
Drag and Drop your image into the search box. Or use the little camera icon.
Click on the uploaded image at the very top.
Use the "Size" filter to find larger images. You may need to change it if nothing shows up.
Look through and download the best-looking one. Some heuristics are: larger resolution, larger file size, and lossless file format, such as PNG or TIFF.
Note: none of the heuristics above directly indicate image quality. You need to use your eyes. People often distort the file by a) taking screenshots or b) saving a small image larger than it actually is / stretching the image.
Hope this helped!