Using fast bucket fill instead of contour selection
Note: This tutorial is also available in PDF.
Add an alpha channel
Some image types lack a transparency channel; JPG for example. If this is the case, add an alpha transparency channel.
This is done by selecting Layer → Tranparency → Add Alpha Channel.
Bucket fill with colour [optional]
The next step ...
You can't save transparency to a .jpg. The file format simply doesn't support it. Anything that is transparent will become white when saved to a .jpeg.
Try .png or .gif, those file formats do accept transparency.
Indeed you should perform right selection.
Select->Color Range and click on the spot colored with color you want to select - you will see the change on the preview screen.
Also, you can choose the color from sampled colors drop down menu
Fuzziness should be set to 0.
If you press SHIFT while selecting (you can also click Shift and drag of the image) ...
Double click your background layer in the layer pallet (to make it into a standard layer)
Choose Selection -> Color Range
Click in the white area of the image
Bring the fuzziness up around 90
Hit DELETE and there you go!
First you'll want to desaturate the image (CMD+SHIFT+U), this removes any color and makes it easier to achieve pure white.
With your file open, choose Image->Adjustments->Levels. You'll get this:
Now bring the two outer triangles in like this (you'll need to play around with this until you get something you like):
You should end up with this!
I came up with a nice method for cleaning up pictures like this, and it works even when the background or lighting is uneven (that is, far worse cases than the example in this question) and it retains the colour.
My instructions are based on the Gimp, but it would be very similar in other programs like Photoshop.
EDIT: Gimp has a filter called "Difference ...
Advanced hair extraction tutorial
First off, plugins and simpler methods are available. This is if you want to get higher quality results. It is largely the same as ACEkin's answer except going into details and with visuals.
I'll be using this photo from Photo by
Ariana Prestes on Unsplash.com:
Note: I'm going to be doing the body in a separate layer so I'...
In my opinion, the Magic Wand tool is about the worst method for extracting a background in 95% of all use cases. Unfortunately, I realize it is the "go to" method for many users. However, it's not often the "best" method, in fact it's among the worst. The Magic Wand method can work for hard edged objects without any cast shadows. But ...
You can do this with GIFsicle, using the following options:
gifsicle -U --disposal=previous --transparent="#ffffff" -O2 anim.gif > anim_trans.gif
where anim.gif and anim_trans.gif are the source and destination file names, and #ffffff is the hex code of the color you want to make transparent (here, pure white).
(The important options here are -U / --...
There are different ways to do this, but the way I would do it in GIMP is roughly:
Color erase tool to remove the bulk of the sepia color.
Manual erasing of dark spots which are darker than light "image" areas, as these can't be done using levels.
Levels to tidy up.
Final color adjustments based on the image properties
In your case, the blue areas might ...
Adobe changed the Delete/Backspace key functionality in Photoshop CS6 when you press the Delete/Backspace key on a locked Background layer.
Since pressing the Delete/Backspace key on a locked background layer merely filled the selection with the background color, Adobe changed the functionality to provide more options when hitting the key. By bringing up ...
Sketch 3 does have some bitmap editing options, but they are very limited.
Here's more about Bitmap editing in Sketch.
To start editing an image, select it on the canvas and double-click. You will see the inspector update with a few special tools.
You might wanna try your luck with Magic wand and then the Vectorize option below it. Although you'd ...
One of the most accurate, yet reasonably easy one is by using one of the (modified) RGB channels of the image as a mask:
Load your image (I'll be using one I found here) into PS, click on channels tab in color panel or if you don't see it, window > channels
Select the channel with most contrast - we ar going to use it as a mask, so focus on the edges (...
Since this is a relatively simple shape, I would just outline it with the pen tool and convert to a selection. Do note the little details around the corners and side buttons though. I would say that would take me a couple minutes at most.
Ramp the contrast up with curves.
Select your image and press Ctrl-M. This will bring up the curves dialog.
Move the top point left and the bottom point right until your image becomes black and white. (that rhymes!)
Here are the steps I took:
Duplicate the base layer and select the copy.
Apply an edge detect filter (Filters -> Edge-Detect -> Edge...)
using these settings:
My goal here is to get clear contrast between my object and my background. I found Sobel worked the best and simply fiddled until I got this result.
Threshold the colors (Colors -> Threshold...) ...
1 - Make a quick selection with quick selection tool (w)
2 - Edit your selection select> refine edge
3 - Choose On layers View mode
4 - Define Edge detection to a correct radius (depends on resolution of your image), check Smart radius
5 - Adjust edge with different variables.
6 - Use Refine radius tool (E) on hair or fur
6 - Sometimes, you will ...
If you have Photoshop CC, then you could use the Select and Mask functionality to refine a selection made with the Magic Wand.
Select the Magic Wand, deselect the "Contiguous" option, set the Tolerance to 20, and click on a white area
Select > Invert
Click on Select and Mask, set the View to: On Black, at 100%
Select the Refine Edge Brush ...
Alpha blending is:
Cout = α * CFG+(1-α) * CBG
Now there are two alphas on the image: a full transparency and the object transparency. The first order of business is to calculate the full transparency. Because we know the color and structure of the checker, we get a system of equations out of two pixels that have the same color.
C = α * CFGdark+(1-α) * ...
This is very easy in Gimp. Just use the bucket tool to fill the background white, and export. Or if you want to go one stage further, then after that, use the select with the same colour tool, press delete (Making sure that your image has an alpha channel) add a new white layer, merge down and export as a jpg, png or whatever.
The easiest way you can do this is by unchecking the contiguous (marked yellow in screenshot) location when selecting the white colour with magic wand. This will select only those areas which you want. To get exact colour or colour range you can set the Tolerance as per your image.
Here is an screenshot with my imaginary image.
I opened a few of the SVGs in Inkscape, the grid is just an object. In Inkscape, just single click the grid and press the Delete key.
You can single click and drag the grid, just to make certain that you selected it and not part of the icon.
jPeg images save automatically with a flat solid background. You will be able to achieve saving your image with a transparent background to .png format.
It won't work with JPEG format.
Some reference to assist transparent background
For sending a document to be printed, don't use PNG as the export format. There are three reasons for this:
A printing press uses CMYK, and PNG is an RGB-only format.
If your document contains text, that text will be rasterized and will print at the resolution of your PNG (perhaps 300 ppi) instead of the 2800 dpi at which live text or vector information is ...
I don't believe that the option exists as print-layout software is focused on laying ink on paper. Since "white" is the absence of ink, it acts as a transparent background.
Keep on mind that unless you are laying a base of ink as a spot color on top of your specialty paper, you will not have any "white" areas in your print. In fact all non-black colors will ...
For people who don't have Adobe Photoshop, here's a free and cross-platform alternative:
Using ImageMagick, it can be done in command line
convert lQchR.png -auto-level -white-threshold 78% fish.png
This may require some fine tuning of the white threshold value, but it's quicker than GUI especially when you have multiple pictures:
convert *.png -auto-...
3 ways to do this:
Use Magic Erase Tool in Photoshop and adjust the Tolerance (Erase Range).
Magic Wand Tool
Go to Select option form the menu
Click "Load Selection"
Again go to Select option from the menu click "Color Range"
Select your image's white area with the help of color picker
Delete the selected area.