I'm really new to Photoshop, but I use Indesign and Illustrator regularly.  I have a picture of a product (books basically) that have a white background and I need that background to be transparent. I used the quick selection tool to select all the white space, then selected the inverse, cut and paste into a new file with a transparent background. When I do this the image ends up looking different-- kinda grainy, ragged edges. What is the best way to change the background to transparent without losing the image quality?   Here are links to the photos  Original:       After trying to remove background:
In Photoshop I've taken Magic Wand as far as I can, I think. Now I'm left with this grayish edge around the coffee saucer. How do I remove it? I've tried altering tolerance in Magic Wand but don't seem able to get it. Any suggestions please?
What is the difference between linear regression and logistic regression? What is the difference between linear regression and logistic regression?  When would you use each? Shift + Control + Space doesn't seem to work anymore. Grub does not show a Windows 8 option after dual boot So, I've successfully dual-booted my Windows 8 machine with Ubuntu 12.04 . However, I still don't have a convenient method of choosing what OS to load at boot time.  After installing Ubuntu, my computer still loads Windows 8 directly. I then added grubx64.efi to the white list of my boot loader. But after that, my machine loads Ubuntu directly without even a shadow of GRUB showing up!  I used boot-repair and I got this paste.ubuntu URL: . After running boot-repair (and re-white listing the grubx64.efi file), GRUB now shows up but without any Windows 8 option!  Lastly, I ran sudo fdisk -l and it gave me this:  WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.   Disk /dev/sda: 750.2 GB, 750156374016 bytes 255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x6396389f     Device Boot      Start         End      Blocks   Id  System /dev/sda1               1  1465149167   732574583+  ee  GPT Partition 1 does not start on physical sector boundary.   I'm guessing my problem has something to do with the warning from fdisk above but I don't know what to do with it. How do I proceed now?  Edit  My etc/default/grub is as follows:  # If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: #   info -f grub -n 'Simple configuration'  GRUB_DEFAULT=0 #GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2&gt; /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" GRUB_CMDLINE_LINUX=""  # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"  # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console  # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480  # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true  # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true"  # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1"   Also, just for the record,  in installing my dual-boot. The tutorial (which uses, 11.10, I must note), doesn't mention anything about this problem. Is there anything there I shouldn't have done? How to make 'python' program command execute Python 3? I am wondering, given the minimal polynomial of $A$, what can we say about the minimal polynomial of $A^n$?  I know that if we were looking at the roots of the characteristic polynomial ie eigenvalues then the roots of the characteristic polynomial of $A^n$ would be $nth$ powers of the eigenvalues so again these are roots of the minimal polynomial also. I am trying to split a selected polygon ("regions") with a selected line from another layer ("streets") in QGIS 3.8.3. In the example below, I want to split the selected polygon coloured in yellow with the street pointed at by the blue arrow.    After reading the post , I realized I can't find it either. I installed the plugin, but the tool seems to be missing from my toolbar: What is XLNC an example of? XS sounds like excess, B4 sounds like before, XLNC sounds like excellency, etc.  What are these wordplays called? Honey changing into unusable, hardened clump Phase Potentials Looking to get a explanation of the following solution.   $x'=sinx$ I understand that you must integrate $sinx$ and then take the negative of it making it $v(x)=cos(x) + c = cos(x)$ with $c=0$. However I am having problems understanding the equilibrium points.   The equilibrium points of this system are,  $$x^*=kz$$ $x*=kz$ k is even, this is unstable $x^*=kz$ k is odd, are stable  Why is it unstable when even and stable when even? In the Stack Overflow podcast #36 (), this opinion was expressed: Once you understand how easy it is to set up a state machine, you’ll never try to use a regular expression inappropriately ever again. I've done a bunch of searching.  I've found some academic papers and other complicated examples, but I'd like to find a simple example that would help me understand this process.  I use a lot of regular expressions, and I'd like to make sure I never use one &quot;inappropriately&quot; ever again. Okay, this should be super easy to do but I just can't find the way.  I have a background image with a solid colour layer on top of it, and I would like to add text on top of everything in such a way that the filling of the text is the image in the background. I have tried selecting the text shape and deleting that selection shape in the solid colour layer, but it just looks wrong.   Can anyone help me with this? Many thanks in advance. Why is the work done on a charge calculated from infinity? Why is the work done on a charge calculated from infinity to a point? Why not from one particular point to other? Creating geodatabase feature class using geodatabase table schema with ArcPy? Is there a way in ArcPy to create an empty polygon geodatabase feature class that will acquire the schema of a geodatabase table?  I know that it's possible in ArcCatalog (New -> Feature Class and then import all the fields from a table) but I wonder if it can be written in a Python script.  The CreateFeatureclass_management tool allows only Feature Layers as schema templates. A calligraphic font with small (lowercase) letters Is there a widely available calligraphic font that (1) contains small (lowercase) letters and (2) has a recognizably calligraphic capital letter O?  Background. (1) In mathematics (algebraic geometry), , the latter being written in calligraphic script (standard notation for sheaves). However, most books end up typesetting the sheaf as follows    pulling the small letters from the italics of a completely different font.  (2) The calligraphic capital letter O plays a special role in algebraic geometry, too, and most authors insist on it being recognizably calligraphic (i.e. not just a closed round loop)    Edit. The following are achieved with extra kerning from @egreg's and @UlrikeFischer's answers (in chronological order)    @egreg's answer  \makeatletter \DeclareFontEncoding{LS1}{}{} \DeclareFontSubstitution{LS1}{stix}{m}{n} \DeclareMathAlphabet{\mathcal}{LS1}{stixscr}{m}{n} \makeatother  \DeclareMathOperator{\sHom}{\mathcal{H\mkern-7mu o\mkern-2.5mu m\mkern-1.5mu}} \DeclareMathOperator{\sExt}{\mathcal{E\mkern-4.5mu x\mkern-2.5mu t\mkern-1mu}} \DeclareMathOperator{\sEnd}{\mathcal{E\mkern-4mu n\mkern-4.5mu d\mkern-1mu}}       @UlrikeFischer's answer  \DeclareFontFamily{U}{mathc}{} \DeclareFontShape{U}{mathc}{m}{it}% {&lt;-&gt;s*[1.03] mathc10}{} \DeclareMathAlphabet{\mathcal}{U}{mathc}{m}{it}  \DeclareMathOperator{\sHom}{\mathcal{H\mkern-3mu om}} \DeclareMathOperator{\sExt}{\mathcal{E\mkern-3mu xt}} \DeclareMathOperator{\sEnd}{\mathcal{E\mkern-3mu nd}} Sign of determinant when using $det A^\top A$ We have been given matrix: $$A =          \begin{pmatrix}         a&amp; b&amp; c &amp;d \\         b &amp;−a&amp; d&amp; −c\\         c&amp; −d &amp;−a&amp; b \\         d &amp;c&amp; −b&amp; −a\\         \end{pmatrix}     $$ ...and have been asked to calculate $\det(A)$ using $AA^T$.  We see that:  $$AA^T=\begin{pmatrix}         a^2+ b^2+ c^2+ d^2&amp; 0&amp; 0&amp;0\\         0 &amp;a^2+ b^2+ c^2+ d^2&amp; 0&amp; 0\\         0&amp; 0 &amp;a^2+ b^2+ c^2+ d^2&amp; b \\        0 &amp;0&amp; 0&amp; a^2+ b^2+ c^2+ d^2\\         \end{pmatrix}     $$   So, $\det(AA^T)= (a^2+ b^2+ c^2+ d^2)^4$  Now which should I choose: $(a^2+ b^2+ c^2+ d^2)^2 $ or $ -(a^2+ b^2+ c^2+ d^2)^2$ ?  Please explain me which one and why. Do virtual particles actually physically exist? Why $\sqrt{-1 \cdot {-1}} \neq \sqrt{-1}^2$? I know there must be something unmathematical in the following but I don't know where it is: \begin{align} \sqrt{-1} &amp;= i \\\\\ \frac1{\sqrt{-1}} &amp;= \frac1i \\\\  \frac{\sqrt1}{\sqrt{-1}} &amp;= \frac1i \\\\  \sqrt{\frac1{-1}} &amp;= \frac1i \\\\  \sqrt{\frac{-1}1} &amp;= \frac1i \\\\  \sqrt{-1} &amp;= \frac1i \\\\  i &amp;= \frac1i \\\\  i^2 &amp;= 1 \\\\  -1 &amp;= 1 \quad !!? \end{align} Design problem - Implement an approval process on case, which sends email to approver showing some additional info, which should not be visible to case owner/agent (who clicked on "Submit for approval" button).  Possible solution - All that additional info will not be stored on Case (otherwise agent will also be able to see it). I am creating a child object to case, where all that additional info be stored. We can make sure agent does not have access to that child object (lets call it ChildObj).   In the email template used, we can include info about that child object. From what i understand, standard email templates dont allow cross object reference. We probably need to use visualforce email templates.  Questions -  1) Can anyone see/point out any issues with that design? 2) I am very new to salesforce. Can anyone give me any example of how i will access child record's field? I mean there won't be any lookup or anything to child object, right? How do i access a field on the child object? Any clue would be helpful It is commonly stated that there are four fundamental forces, or interactions, in nature. It is natural to consider which of those is responsible for the normal force we meet in elementary physics. What is the nature of the force exerted on a body by the floor on which it rests?  Of the four forces, the only one that seems relevant is the electromagnetic force, and I always assumed the repelling force in question is ultimately the EM one. The Wikipedia article on  seems to agree:     Molecular and quantum physics show that the electromagnetic force is the fundamental interaction responsible for contact forces.    An alternative explanation is that the force results from Pauli's Exclusion Principle; however, reasonable as it may seem, it doesn't seem to answer the question of what force is actually at play here. The exclusion principle isn't a force, or at least it's not normally described as such.  I've recently come across a rather forcefully presented argument that states that the normal force is a macroscopic force that is not directly reducible to the EM force, or to any of the other forces; rather, it does indeed result from Pauli's Exclusion Principle by way of interaction of electron wave functions. The argument further claims that attempts to correct the Wikipedia article have met with the usual "source needed" objections, and that this topic is either misunderstood by or poorly covered in the standard texts.  (The argument can be found ).   Which way is it? What is the "show desktop" keyboard shortcut? I just upgraded to 11.10 from 11.04. Previously the shortcut to show the desktop was Super +D (same as in Windows), But now it is not working. What is the new shortcut?