How can I turn a black and white picture into a colorful one?

Posted on 2001-07-18
Medium Priority
Last Modified: 2010-04-06
Hi,dear experts:
    I know how to turn a colorful picture into a black and white one.For example:pixel.r:=(pixel.r+pixel.g+pixel.b)/3;and pixel.g:=pixel.r;pixel.b:=pixel.r;right?
      But for a opposite transformation,what shall I do?
     How can I turn a black and whithe picture into a colorful one?Thank you for your kind answere.I will appreciate them very much.
Question by:feixiangniao

Accepted Solution

StevenB earned 800 total points
ID: 6296786
 In terms of pure graphics programming this cannot be done, there is no way of establishing the correct colour of a greyscale pixel.

  If you ware to seed the greyscale image with some colours then you could write an inteligent tinting algorhythm that searched for image element borders and coloured the image appropriately, but this would be a massive task.
LVL 27

Expert Comment

ID: 6296985
take a look to


i guess you may find there many tips

meikl ;-)
LVL 20

Expert Comment

ID: 6297042
Just let's do some math:

If you have 3 numbers like e.g. 250, 200 and 150. Now you calculate (250 + 200 + 150) / 3 = 200. So now the result is 200.

How would you go backwards? How can we (or a program) know that 200 should be resolved to 250, 200 and 150? It's simply impossible mathematical. When doing the (r+g+b)/3 we're losing information that we can't recover.

Regards, Madshi.
Get your problem seen by more experts

Be seen. Boost your question’s priority for more expert views and faster solutions


Expert Comment

ID: 6297117
 If you already have the colour image and have converted it to greyscale for display purposes, then you could cache the colour version in order to reverse the operation.
LVL 35

Expert Comment

ID: 6300930
If you had a black and white image of me, and wanted to make it "colorful" , would you know what color to make my shirt ? How would a program know what color to make my shirt, pants, hair, ect?. . so the opposite transformation of a grayscale image requires the "color" information for that image. . . and by the way, the formula used for getting B&W TV is (0.30 * Red) + (0.59 * Green) + (0.11 * Blue) which gives a truer grayscale image
LVL 26

Expert Comment

by:Russell Libby
ID: 8703580
No comment has been added lately, so it's time to clean up this TA.
I will leave a recommendation in the Cleanup topic area that this question is:

Accept StevenB's comment as answer

Please leave any comments here within the next seven days.
Thank you,

EE Cleanup Volunteer

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
This is an update to some code that someone else posted on Experts Exchange. It is an alternate approach, I think a little easier to use, & makes sure that things like the Task Bar will update.
The video provides a quick and easy steps to migrate MBOX file to well known Outlook PST and Office 365. Besides this, it also supports and migrates more than 20 email clients of MBOX which include AppleMail, Opera, Thunderbird and SeaMonkey effortl…
Free Data Recovery software is an advanced solution from Kernel Tools to recover data and files such as documents, emails, database, media and pictures, etc. It supports recovery from physical & logical drive after a hard disk crash, accidental/inte…

624 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question