CODEWITHSUNDEEP
c#imagescale
user1104916
user1104916

Reputation: 113

How to scale down an image to a maxSize?

What I want is to redure picture size to 480k pixels or less for any picture with size greater than 480k pixels;

-- maxSize = 480k
-- picture1.Size = 1600*300 = 480k = maxSize => that's OK.
-- picture2.Size = 2600*200 = 520k => problem (should be reduced to maxSize or less).

picture2.Size / maxSize = 1.083

picture2.Size/1.083 = 480148 (~= maxSize) => that's OK.

Let's suppose that 1.083 is the ratio for picture resizing: ratio = 1.083;

How to apply this ratio to keep picture aspect ratio?

Upvotes: 0

Views: 140

Answers (2)

Save
Save

Reputation: 11928

You just want to solve the system:

newWidth * newHeight = maxSize;
newWidth / newHeight = picture2.Width / picture2.Height

and the solution is :

double newWidth = Math.Sqrt(picture2.Width * maxSize / picture2.Height);
double newHeight = Math.Sqrt(picture2.Height * maxSize / picture2.Width);

this way, the aspect ratio of picture2 will be preserved, and the size won't exceed maxSize

Upvotes: 1

unrealsoul007
unrealsoul007

Reputation: 4077

(2600-x)/(200-y) = 2600/200 and x*y = 1.083

Now the picture can be rescaled to a size less than maxSize and aspect ratio also remains the same.

Upvotes: 0

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