My preferred method for taking screenshots in Chrome was just updated with a new feature that extends its reach. I use Awesome Screenshot to capture parts of or entire pages in Chrome, a process which became more efficient last year when an autosave feature was added. Now, Awesome Screenshot lets you not only capture and annotate screenshots you took of Chrome, but it also lets you load local image files to annotate using Chrome.
To select a file, click on the Awesome Screenshot button to the right of Chrome's URL bar and choose "Select a local image," which opens a new tab in Chrome with an area for you to drag and drop a PNG or a JPEG file. (Alternatively, you can click within the box to browse for a file.)
Once you have loaded your image, you can then use Awesome Screenshot's editing tools to crop, draw a rectangle or oval or freehand shape, add arrows or lines, blur a section, or add text. There is no selection of fonts from which to choose, but you do get your choice of 12 colors for your annotations.
Lastly, the crop tool has been improved, providing pixel counts for width and height that you can edit to your precise wants and needs.