Resizing an Image without losing any quality

Question

How can I resize an image  with the image quality unaffected

User · Answer

Unless you resize up  you cannot do this with raster graphics   What you can do with good filtering and smoothing is to resize without losing any noticable quality   You can also alter the DPI metadata of the image  assuming it has some  which will keep exactly the same pixel count  but will alter how image editors think of it in  real-world  measurements   And just to cover all bases  if you really meant just the file size of the image and not the actual image dimensions  I suggest you look at a lossless encoding of the image data  My suggestion for this would be to resave the image as a  png file  I tend to use paint as a free transcoder for images in windows  Load image in paint  save as in the new format

User · Answer

You can t resize an image without losing some quality  simply because you are reducing the number of pixels    Don t reduce the size client side  because browsers don t do a good job of resizing images    What you can do is programatically change the size before you render it  or as a user uploads it   Here is an article that explains one way to do this in c   http   www codeproject com KB GDI-plus imageresize aspx

User · Answer

See if you like the image resizing quality of this open source ASP NET module  There s a live demo  so you can mess around with it yourself  It yields results that are  to me  impossible to distinguish from Photoshop output  It also has similar file sizes - MS did a good job on their JPEG encoder

User · Answer

Are you resizing larger  or smaller    By a small   or by a larger factor like 2x  3x   What do you mean by quality for your application    And what type of images - photographs  hard-edged line drawings  or what    Writing your own low-level pixel grinding code or trying to do it as much as possible with existing libraries   net or whatever    There is a large body of knowledge on this topic  The key concept is interpolation     Browsing recommendations    http   www all-in-one ee  dersch interpolator interpolator html   http   www cambridgeincolour com tutorials image-interpolation htm   for C   https   secure codeproject com KB GDI-plus imageprocessing4 aspx display PrintAll amp fid 3657 amp df 90 amp mpp 25 amp noise 3 amp sort Position amp view Quick amp fr 26 amp select 629945   this is java-specific but might be educational - http   today java net pub a today 2007 04 03 perils-of-image-getscaledinstance html

User · Answer

Here you can find also add watermark codes in this class        public class ImageProcessor               public Bitmap Resize Bitmap image  int newWidth  int newHeight  string message                        try                               Bitmap newImage   new Bitmap newWidth  Calculations image Width  image Height  newWidth                     using  Graphics gr   Graphics FromImage newImage                                         gr SmoothingMode   SmoothingMode AntiAlias                      gr InterpolationMode   InterpolationMode HighQualityBicubic                      gr PixelOffsetMode   PixelOffsetMode HighQuality                      gr DrawImage image  new Rectangle 0  0  newImage Width  newImage Height                         var myBrush   new SolidBrush Color FromArgb 70  205  205  205                         double diagonal   Math Sqrt newImage Width   newImage Width   newImage Height   newImage Height                        Rectangle containerBox   new Rectangle                         containerBox X    int  diagonal   10                       float messageLength    float  diagonal   message Length   1                       containerBox Y   - int  messageLength   1 6                        Font stringFont   new Font  verdana   messageLength                        StringFormat sf   new StringFormat                         float slope    float  Math Atan2 newImage Height  newImage Width    180   Math PI                        gr RotateTransform slope                       gr DrawString message  stringFont  myBrush  containerBox  sf                       return newImage                                              catch  Exception exc                                throw exc                                   public int Calculations decimal w1  decimal h1  int newWidth                        decimal height   0              decimal ratio   0                if  newWidth  lt  w1                                ratio   w1   newWidth                  height   h1   ratio                   return height To lt int gt                                if  w1  lt  newWidth                                ratio   newWidth   w1                  height   h1   ratio                  return height To lt int gt                                return height To lt int gt

User · Answer

I believe what you re looking to do is  Resize Resample  your images  Here is a good site that gives instructions and provides a utility class That I also happen to use    http   www codeproject com KB GDI-plus imgresizoutperfgdiplus aspx

User · Answer

See if you like the image resizing quality of this open source ASP NET module  There s a live demo  so you can mess around with it yourself  It yields results that are  to me  impossible to distinguish from Photoshop output  It also has similar file sizes - MS did a good job on their JPEG encoder

User · Answer

There is something out there  context aware resizing  don t know if you will be able to use it  but it s worth looking at  that s for sure  A nice video demo  Enlarging appears towards the middle  http   www youtube com watch v vIFCV2spKtg  Here there could be some code  http   www semanticmetadata net 2007 08 30 content-aware-image-resizing-gpl-implementation   Was that overkill  Maybe there are some easy filters you can apply to an enlarged image to blur the pixels a bit  you could look into that

User · Answer

There is something out there  context aware resizing  don t know if you will be able to use it  but it s worth looking at  that s for sure  A nice video demo  Enlarging appears towards the middle  http   www youtube com watch v vIFCV2spKtg  Here there could be some code  http   www semanticmetadata net 2007 08 30 content-aware-image-resizing-gpl-implementation   Was that overkill  Maybe there are some easy filters you can apply to an enlarged image to blur the pixels a bit  you could look into that

User · Answer

Unless you resize up  you cannot do this with raster graphics   What you can do with good filtering and smoothing is to resize without losing any noticable quality   You can also alter the DPI metadata of the image  assuming it has some  which will keep exactly the same pixel count  but will alter how image editors think of it in  real-world  measurements   And just to cover all bases  if you really meant just the file size of the image and not the actual image dimensions  I suggest you look at a lossless encoding of the image data  My suggestion for this would be to resave the image as a  png file  I tend to use paint as a free transcoder for images in windows  Load image in paint  save as in the new format

User · Answer

I believe what you re looking to do is  Resize Resample  your images  Here is a good site that gives instructions and provides a utility class That I also happen to use    http   www codeproject com KB GDI-plus imgresizoutperfgdiplus aspx

User · Answer

As rcar says  you can t without losing some quality  the best you can do in c  is   Bitmap newImage   new Bitmap newWidth  newHeight   using  Graphics gr   Graphics FromImage newImage         gr SmoothingMode   SmoothingMode HighQuality      gr InterpolationMode   InterpolationMode HighQualityBicubic      gr PixelOffsetMode   PixelOffsetMode HighQuality      gr DrawImage srcImage  new Rectangle 0  0  newWidth  newHeight

User · Answer

You can t resize an image without losing some quality  simply because you are reducing the number of pixels    Don t reduce the size client side  because browsers don t do a good job of resizing images    What you can do is programatically change the size before you render it  or as a user uploads it   Here is an article that explains one way to do this in c   http   www codeproject com KB GDI-plus imageresize aspx

User · Answer

You can t resize an image without losing some quality  simply because you are reducing the number of pixels    Don t reduce the size client side  because browsers don t do a good job of resizing images    What you can do is programatically change the size before you render it  or as a user uploads it   Here is an article that explains one way to do this in c   http   www codeproject com KB GDI-plus imageresize aspx

User · Answer

There is something out there  context aware resizing  don t know if you will be able to use it  but it s worth looking at  that s for sure  A nice video demo  Enlarging appears towards the middle  http   www youtube com watch v vIFCV2spKtg  Here there could be some code  http   www semanticmetadata net 2007 08 30 content-aware-image-resizing-gpl-implementation   Was that overkill  Maybe there are some easy filters you can apply to an enlarged image to blur the pixels a bit  you could look into that

User · Answer

Are you resizing larger  or smaller    By a small   or by a larger factor like 2x  3x   What do you mean by quality for your application    And what type of images - photographs  hard-edged line drawings  or what    Writing your own low-level pixel grinding code or trying to do it as much as possible with existing libraries   net or whatever    There is a large body of knowledge on this topic  The key concept is interpolation     Browsing recommendations    http   www all-in-one ee  dersch interpolator interpolator html   http   www cambridgeincolour com tutorials image-interpolation htm   for C   https   secure codeproject com KB GDI-plus imageprocessing4 aspx display PrintAll amp fid 3657 amp df 90 amp mpp 25 amp noise 3 amp sort Position amp view Quick amp fr 26 amp select 629945   this is java-specific but might be educational - http   today java net pub a today 2007 04 03 perils-of-image-getscaledinstance html

User · Answer

private static Image resizeImage Image imgToResize  Size size        int sourceWidth   imgToResize Width      int sourceHeight   imgToResize Height       float nPercent   0      float nPercentW   0      float nPercentH   0       nPercentW     float size Width    float sourceWidth       nPercentH     float size Height    float sourceHeight        if  nPercentH  lt  nPercentW          nPercent   nPercentH      else         nPercent   nPercentW       int destWidth    int  sourceWidth   nPercent       int destHeight    int  sourceHeight   nPercent        Bitmap b   new Bitmap destWidth  destHeight       Graphics g   Graphics FromImage  Image b       g InterpolationMode   InterpolationMode HighQualityBicubic       g DrawImage imgToResize  0  0  destWidth  destHeight       g Dispose         return  Image b      from here

User · Answer

Unless you re doing vector graphics  there s no way to resize an image without potentially losing some image quality

User · Answer

As rcar says  you can t without losing some quality  the best you can do in c  is   Bitmap newImage   new Bitmap newWidth  newHeight   using  Graphics gr   Graphics FromImage newImage         gr SmoothingMode   SmoothingMode HighQuality      gr InterpolationMode   InterpolationMode HighQualityBicubic      gr PixelOffsetMode   PixelOffsetMode HighQuality      gr DrawImage srcImage  new Rectangle 0  0  newWidth  newHeight

User · Answer

Unless you re doing vector graphics  there s no way to resize an image without potentially losing some image quality

User · Answer

Here is a forum thread that provides a C  image resizing code sample  You could use one of the GD library binders to do resampling in C

User · Answer

See if you like the image resizing quality of this open source ASP NET module  There s a live demo  so you can mess around with it yourself  It yields results that are  to me  impossible to distinguish from Photoshop output  It also has similar file sizes - MS did a good job on their JPEG encoder

User · Answer

You can t resize an image without losing some quality  simply because you are reducing the number of pixels    Don t reduce the size client side  because browsers don t do a good job of resizing images    What you can do is programatically change the size before you render it  or as a user uploads it   Here is an article that explains one way to do this in c   http   www codeproject com KB GDI-plus imageresize aspx

User · Answer

private static Image resizeImage Image imgToResize  Size size        int sourceWidth   imgToResize Width      int sourceHeight   imgToResize Height       float nPercent   0      float nPercentW   0      float nPercentH   0       nPercentW     float size Width    float sourceWidth       nPercentH     float size Height    float sourceHeight        if  nPercentH  lt  nPercentW          nPercent   nPercentH      else         nPercent   nPercentW       int destWidth    int  sourceWidth   nPercent       int destHeight    int  sourceHeight   nPercent        Bitmap b   new Bitmap destWidth  destHeight       Graphics g   Graphics FromImage  Image b       g InterpolationMode   InterpolationMode HighQualityBicubic       g DrawImage imgToResize  0  0  destWidth  destHeight       g Dispose         return  Image b      from here

User · Answer

Here is a forum thread that provides a C  image resizing code sample  You could use one of the GD library binders to do resampling in C

User · Answer

Are you resizing larger  or smaller    By a small   or by a larger factor like 2x  3x   What do you mean by quality for your application    And what type of images - photographs  hard-edged line drawings  or what    Writing your own low-level pixel grinding code or trying to do it as much as possible with existing libraries   net or whatever    There is a large body of knowledge on this topic  The key concept is interpolation     Browsing recommendations    http   www all-in-one ee  dersch interpolator interpolator html   http   www cambridgeincolour com tutorials image-interpolation htm   for C   https   secure codeproject com KB GDI-plus imageprocessing4 aspx display PrintAll amp fid 3657 amp df 90 amp mpp 25 amp noise 3 amp sort Position amp view Quick amp fr 26 amp select 629945   this is java-specific but might be educational - http   today java net pub a today 2007 04 03 perils-of-image-getscaledinstance html

User · Answer

Unless you re doing vector graphics  there s no way to resize an image without potentially losing some image quality

User · Answer

Unless you re doing vector graphics  there s no way to resize an image without potentially losing some image quality

User · Answer

I believe what you re looking to do is  Resize Resample  your images  Here is a good site that gives instructions and provides a utility class That I also happen to use    http   www codeproject com KB GDI-plus imgresizoutperfgdiplus aspx

User · Answer

Here is a forum thread that provides a C  image resizing code sample  You could use one of the GD library binders to do resampling in C

User · Answer

Here is a forum thread that provides a C  image resizing code sample  You could use one of the GD library binders to do resampling in C

User · Answer

I believe what you re looking to do is  Resize Resample  your images  Here is a good site that gives instructions and provides a utility class That I also happen to use    http   www codeproject com KB GDI-plus imgresizoutperfgdiplus aspx

User · Answer

Unless you resize up  you cannot do this with raster graphics   What you can do with good filtering and smoothing is to resize without losing any noticable quality   You can also alter the DPI metadata of the image  assuming it has some  which will keep exactly the same pixel count  but will alter how image editors think of it in  real-world  measurements   And just to cover all bases  if you really meant just the file size of the image and not the actual image dimensions  I suggest you look at a lossless encoding of the image data  My suggestion for this would be to resave the image as a  png file  I tend to use paint as a free transcoder for images in windows  Load image in paint  save as in the new format

User · Answer

As rcar says  you can t without losing some quality  the best you can do in c  is   Bitmap newImage   new Bitmap newWidth  newHeight   using  Graphics gr   Graphics FromImage newImage         gr SmoothingMode   SmoothingMode HighQuality      gr InterpolationMode   InterpolationMode HighQualityBicubic      gr PixelOffsetMode   PixelOffsetMode HighQuality      gr DrawImage srcImage  new Rectangle 0  0  newWidth  newHeight

User · Answer

See if you like the image resizing quality of this open source ASP NET module  There s a live demo  so you can mess around with it yourself  It yields results that are  to me  impossible to distinguish from Photoshop output  It also has similar file sizes - MS did a good job on their JPEG encoder

User · Answer

There is something out there  context aware resizing  don t know if you will be able to use it  but it s worth looking at  that s for sure  A nice video demo  Enlarging appears towards the middle  http   www youtube com watch v vIFCV2spKtg  Here there could be some code  http   www semanticmetadata net 2007 08 30 content-aware-image-resizing-gpl-implementation   Was that overkill  Maybe there are some easy filters you can apply to an enlarged image to blur the pixels a bit  you could look into that

User · Answer

Are you resizing larger  or smaller    By a small   or by a larger factor like 2x  3x   What do you mean by quality for your application    And what type of images - photographs  hard-edged line drawings  or what    Writing your own low-level pixel grinding code or trying to do it as much as possible with existing libraries   net or whatever    There is a large body of knowledge on this topic  The key concept is interpolation     Browsing recommendations    http   www all-in-one ee  dersch interpolator interpolator html   http   www cambridgeincolour com tutorials image-interpolation htm   for C   https   secure codeproject com KB GDI-plus imageprocessing4 aspx display PrintAll amp fid 3657 amp df 90 amp mpp 25 amp noise 3 amp sort Position amp view Quick amp fr 26 amp select 629945   this is java-specific but might be educational - http   today java net pub a today 2007 04 03 perils-of-image-getscaledinstance html

User · Answer

Here you can find also add watermark codes in this class        public class ImageProcessor               public Bitmap Resize Bitmap image  int newWidth  int newHeight  string message                        try                               Bitmap newImage   new Bitmap newWidth  Calculations image Width  image Height  newWidth                     using  Graphics gr   Graphics FromImage newImage                                         gr SmoothingMode   SmoothingMode AntiAlias                      gr InterpolationMode   InterpolationMode HighQualityBicubic                      gr PixelOffsetMode   PixelOffsetMode HighQuality                      gr DrawImage image  new Rectangle 0  0  newImage Width  newImage Height                         var myBrush   new SolidBrush Color FromArgb 70  205  205  205                         double diagonal   Math Sqrt newImage Width   newImage Width   newImage Height   newImage Height                        Rectangle containerBox   new Rectangle                         containerBox X    int  diagonal   10                       float messageLength    float  diagonal   message Length   1                       containerBox Y   - int  messageLength   1 6                        Font stringFont   new Font  verdana   messageLength                        StringFormat sf   new StringFormat                         float slope    float  Math Atan2 newImage Height  newImage Width    180   Math PI                        gr RotateTransform slope                       gr DrawString message  stringFont  myBrush  containerBox  sf                       return newImage                                              catch  Exception exc                                throw exc                                   public int Calculations decimal w1  decimal h1  int newWidth                        decimal height   0              decimal ratio   0                if  newWidth  lt  w1                                ratio   w1   newWidth                  height   h1   ratio                   return height To lt int gt                                if  w1  lt  newWidth                                ratio   newWidth   w1                  height   h1   ratio                  return height To lt int gt                                return height To lt int gt

User · Answer

As rcar says  you can t without losing some quality  the best you can do in c  is   Bitmap newImage   new Bitmap newWidth  newHeight   using  Graphics gr   Graphics FromImage newImage         gr SmoothingMode   SmoothingMode HighQuality      gr InterpolationMode   InterpolationMode HighQualityBicubic      gr PixelOffsetMode   PixelOffsetMode HighQuality      gr DrawImage srcImage  new Rectangle 0  0  newWidth  newHeight

User · Answer

Unless you resize up  you cannot do this with raster graphics   What you can do with good filtering and smoothing is to resize without losing any noticable quality   You can also alter the DPI metadata of the image  assuming it has some  which will keep exactly the same pixel count  but will alter how image editors think of it in  real-world  measurements   And just to cover all bases  if you really meant just the file size of the image and not the actual image dimensions  I suggest you look at a lossless encoding of the image data  My suggestion for this would be to resave the image as a  png file  I tend to use paint as a free transcoder for images in windows  Load image in paint  save as in the new format

[c#] Resizing an Image without losing any quality

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