No, it does not have much use.
Digital zoom is a restricted form of cropping:
It is always done around the center.
It is constrained to certain fixed increments.
It is limited in quality by the firmware of the camera.
On the other hand, cropping can:
Be of arbitrary size.
Be taken from any part of the image.
Be processed using a variety of state-of-the-...
Q: When is it OK to place the subject in the middle of a picture?
A: Whenever you feel that it works best!
The general rule of not centering your subject is time-honored, and comes from one basic idea: the center of an image is a stable, straightforward place. When you put something there visually, it stays there visually, usually resulting in a static ...
I think an important advantage is saving time. When you happen to shoot hundreds of photos in a row stuck with a lens wider than would be optimal, cropping each one of the images into a smaller size in post processing would be quite tedious - usually you can't do that in batch unless you really don't care about resulting framing. Framing on spot, on the ...
I can't believe no one suggested this yet:
Just use the rectangular marquee to select what you want to crop down to, and COPY it to your clipboard. Then delete the entire layer and PASTE what you copied to a new layer.
This is especially useful if the layer you're cropping is larger than the canvas, in which case the select-inverse technique is messy.
If you don't know the crop boundary then you can use Fred Weinhaus's multicrop script (this script also uses Imagemagick). The script also handles different photo sizes and rotated images.
Example (book covers):
Scanned image (input.tiff):
multicrop input.tiff output.tiff
Same photo will result from using digital zoom or cropping.
Advantage of digital zoom: you don't need a computer to crop it. You can upload straight to Facebook, print it out, etc. Cropping is a very common post-processing technique and this lets you do it easily, on the fly.
Advantages of cropping after the fact: you can take more time to compose the crop ...
It simply means you have cropped a portion of the image but not resized it. This is usually done to demonstrate noise or lens sharpness, where you do not want resizing to affect the image. So you want to show the original pixels, but rather than sharing 4000 x 3000 pixels, you crop out a portion at the same resolution.
So you are correct in your ...
Use a layer mask. Tutorials galore exist on the topic already, eg: http://helpx.adobe.com/photoshop/using/masking-layers.html
Straight from Adobe:
You can add a mask to a layer and use the mask to hide portions of the layer and reveal the layers below. Masking layers is a valuable compositing technique for combining multiple photos into a single image or ...
Here's a solution using python and opencv:
This will crop all the faces it finds in the jpeg photos in whatever folder you run it in, with the padding specified by the left, right, top, bottom variables:
cascPath = "haarcascade_frontalface_default.xml"
# Create the haar cascade
faceCascade = cv2.CascadeClassifier(...
You know when to stop when you are satisfied with the result. There's nothing more to it. It is your image, your feelings, your point of view, your way of expressing yourself.
I don't think there's a definite answer, because this is very subjective.
Also, the "rules" you mentioned are not really rules. They're more like guidelines. You need to know them (...
When you select the crop tool the toolbar offers some features to make cropping to proportions easy:
Pick the Crop tool and in the toolbar pick the crop icon with dropdown arrow, where you'll see presets. Pick one and use it.
No preset exists for the crop you want? Create it by entering the specifics in the fields to the right of the field: width, height, ...
You can also select the area you want to crop to with the rectangular marquee tool, invert your selection, then delete the now selected outside area. This is different from the layer mask in that it completely deletes the surrounding area, whereas the mask makes the surrounding area invisible.
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 ...
@mattdm has given a nice overview. I'll add some specific situations where middle might turn out to give the best composition:
When you have a subject looking straight at camera and no directional lighting, placing the subject to a side would often feel synthetic. Especially so with a tighter crop. Your photo is an example of this category.
Photos with ...
100% crop = 1 to 1 pixel mapping on your screen.
I.e. one pixel from the image maps to one pixel on the screen.
And just to add - by the nature of doing that, you must crop the image, because no regular screen can display the full resolution image from a modern camera (yet?).
Your 200mm will still be a 200mm. It will project the same image on the sensor. In DX mode, all that will happen is the camera will throw away the outer areas of that captured image and retain what would have fallen on a DX sensor. This is something you can do yourself in post-processing, so I don't think there is much benefit (apart from smaller file ...
Note that you can crop JPEG images without having to reencode them if you use tools that work with the JPEG format, such as jpegcrops, jpegcrop, or jpegtran - these tools perform lossless operations on JPEG files, including cropping, concatenation, and certain transformations (e.g. 90-degree rotation) by working with the underlying DCT data (as opposed to ...
Cropping in General
First off, some words about cropping in general. Fundamentally, cropping is not any different than composing in camera. The same general guidelines apply, and the same outcomes can be achieved with cropping as with composing in-camera. An important symmetry that might not be quite so obvious to a beginner.
As with any composition, ...
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:
Relevant example from this forum post:
cd C:\Users\user\Desktop\New\New folder
convert *.jpg -...
When shooting JPEG you usually have to option to select the size and quality of your image. For instance with Nikon cameras you can select Large and Fine. This option will give you the maximum resolution. This is also the resolution of the RAW file so you will not gain any resolution if you shooting at the maximum JPEG quality. Shooting RAW will give you ...
I personally only crop when, aesthetically, it has a lot to do with the subject or the limitations of having to simply take the photograph with the 3:2 aspect ratio with the camera. For example, I took a photo of a mate of mine in landscape when I could have, in hindsight, tilted the tripod mount to portrait and taken it, but because I was in the shoot ...
First you want to start with the best selection possible. Here you have some choices.
Select using lasso, quick select (not ideal unless you want to do lots of adjusting). If you do use these, once you've made the best selection you can, click on the Refine Edge button in the tool bar and use the sliders to inteligently adjust your selection.
Near the ...
Question 1: Does it look good at that size?
Your image will look good because most people will only look at it from afar. If it is at a trade show and depending on where exactly it is, no one may be able to get close to the image.
Much more about this can be read here: How do I generate high quality prints with an ink jet printer?
Using Patrick Hurley's ...
Aspect ratio is only critical when matching to one printed paper size, or maybe to full screen monitor shape. Only one ratio fits another shape. And since many shapes exist, no one ratio number is very important, except for your current match, when it is all important.
Otherwise, if not matching to any specific shape, then it's entirely your choice, how ...
You can do this fairly easily in Picasa. Simply select the Crop option, then "Add Custom Aspect Ratio" at the bottom of the crop options. This will allow you to select a custom size such as 8x8, then export export it as such. Below I have some screenshots to assist.
Never seen an imaging software that could not do that, so yes, you can do this.
Adobe Lightroom has a great tool to do that which is interactive. It does cost money, so I would not buy it just for that (there are excellent reasons to do so though).
Google Picasa is free and can do that. Look for the menu item that says 'Straighten'.
It does not matter ...
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 ...