INtro to Using PHOTOSHOP 6 and BATCH CROPPING

 

 

What is Photoshop?

Photoshop is a powerful image processing and graphics program.  It operates using pixels, which are the smallest units of a digital image.  If you were to magnify (zoom in on) an image displayed in Photoshop, you would see that it consists of a grid of pixels.  There may be hundreds or thousands of pixels in an image, depending on its size and resolution.  Each pixel has a specific color and a location.  Photoshop keeps track of the location of each pixel and its color value, thus, all operations in Photoshop basically involve the selection of individual or groups of pixels, moving them around, and/or changing their color values.

 

 

 

                       

 

 

 

 

Basic things you can do with Photoshop:

• Open a variety of file formats and multiple files at once

• Crop your image- getting rid of unwanted portions

• Flip and/or your rotate your image

• Adjust tonal contrasts, levels, brightness, colors over the entire image, or selected areas.

• Remove or replace parts of your image - touching up.

• Add text using an overlay (layers)

• Reduce or increase color/grayscale (bit) resolution of the image

• Reduce or increase image dimensions and image resolution

• Save files in a variety of formats

• Automate tasks (batch processing)

 

 

 

Tools and Menus:

 

Photoshop provides an image window, tools and palettes, and command menus along the top of the screen.  By using a combination of menu commands and tools, you can create and modify all manner of graphic images.  Many tools have an options palette that can be accessed by double-clicking on them.

 

 

 

Photoshop Tools:

 

 

Working tips:

• Always work on a copy of the original, especially while recording actions.

 

• Always view your image at 100% or larger.  View Menu > Actual Pixels.    You can also Zoom In, Zoom Out, or use the magnifying tool (press Option/Alt key to zoom out).

 

• To Undo operations, choose undo (Edit Menu > Undo) or open the History Palette (Windows  Menu > Show History).  The History palette lists everything you’ve done. To undo, drag each item in the list into the trash symbol in the palette; or, simply go up the list of actions and select the step to which you wish to return.   You can also revert to your previously saved version of your image- File > Revert. 

 

• There are several ways to make copies or duplicate your file: 

            File > Save As

         File > Save a Copy

         Image > Duplicate

 

• Remember to save archive copies of your file before or during stages of processing !

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BATCH CROPPING:  You can use Photoshop to crop your images in case your computer does not have enough RAM to crop through a stack using NIH/Scion Image.

 

1)   Know what to crop:  Look through your stack using NIH Image to assess what you want to crop out.  Select an image from your stack that will allow you to outline a cropping margin that will work for your entire stack.

 

2)   Recording an Action:  In Photoshop, you can automate tasks by recording a sequence of commands while working on an image, then apply them to an entire folder.  A command sequence is called an Action.  To set up an Action, open the Actions palette (Window Menu > Show Actions).  At the top right of this window there is an arrow that will display the Actions Menu.  Some menu icons are also shown at the bottom of the Actions palette.

 

 

 

Create a New Set and name it “Cropping”. 

 

Create a New Action and name it “Cropping Images”.  Before proceeding, make sure you have open a copy of the image you want to crop.  Move the Actions palette aside so that you can work on an image and see both.

 

Click on Record (the record button on the Actions palette -light will turn red).

 

Select the Crop tool from the toolbox, and click-drag the cursor over the area in the image you want to keep. Drag the corner handles (little squares) to resize and position  the cropping frame.

 

 

Once you have set up the cropping frame,

Click on the crop tool once more and choose Crop.  The area outside the cropping frame will be deleted.

 

Press the Stop Button in the Actions Palette.   This turns off recording and you will notice that the Actions Palette now lists the sequence of commands; in this case, just  “Crop”.  You can delete, re-record and insert a new command into an Actions list, so if your Action doesn’t work, you can see where to fix it or start over.  This is why it is important to record on a copy of your image!

 

Close your image window—do not save!

 

    

3)   Batch Processing:  To apply your Cropping Action to all the images in a folder, prepare the folder by placing only the images you want cropped in it.  Open the Actions palette and position it on screen so you can see the commands you are using.

 

Call up the Batch command (File Menu >Automate > Batch)

 

 

 

Select the name of the Actions Set and Action, choose the Source Folder (what you want to process), and choose a destination folder (where you want to save your batched images).  If you choose the same destination and source folder, all your images will be replaced with the new set of cropped images.   Once you have set up your batch options, click OK.   This will begin the automation.  You can watch how Photoshop implements the commands listed in the Actions palette.  To stop the process, you can click on the Stop button on the Actions palette, or press the escape key.