diff --git a/SDWebImageWebPCoder/Classes/SDImageWebPCoder.m b/SDWebImageWebPCoder/Classes/SDImageWebPCoder.m
index 104ee32..89094d7 100644
--- a/SDWebImageWebPCoder/Classes/SDImageWebPCoder.m
+++ b/SDWebImageWebPCoder/Classes/SDImageWebPCoder.m
@@ -96,8 +96,8 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     BOOL _hasAnimation;
     BOOL _hasAlpha;
     BOOL _finished;
-    CGFloat _canvasWidth; // Full Size without thumbnail scale
-    CGFloat _canvasHeight; // Full Size without thumbnail scale
+    CGFloat _canvasWidth;
+    CGFloat _canvasHeight;
     dispatch_semaphore_t _lock;
     NSUInteger _currentBlendIndex;
     BOOL _preserveAspectRatio;
@@ -192,10 +192,14 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
         return nil;
     }
     CGColorSpaceRef colorSpace = [self sd_createColorSpaceWithDemuxer:demuxer];
+    int canvasWidth = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_WIDTH);
+    int canvasHeight = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_HEIGHT);
     
     if (!hasAnimation || decodeFirstFrame) {
         // first frame for animated webp image
-        CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpace preserveAspectRatio:preserveAspectRatio thumbnailSize:thumbnailSize];
+        CGSize scaledSize = SDCalculateThumbnailSize(CGSizeMake(canvasWidth, canvasHeight), preserveAspectRatio, thumbnailSize);
+        // Create thumbnail if need
+        CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpace scaledSize:scaledSize];
         CGColorSpaceRelease(colorSpace);
 #if SD_UIKIT || SD_WATCH
         UIImage *firstFrameImage = [[UIImage alloc] initWithCGImage:imageRef scale:scale orientation:UIImageOrientationUp];
@@ -209,15 +213,10 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
         return firstFrameImage;
     }
     
-    int canvasWidth = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_WIDTH);
-    int canvasHeight = WebPDemuxGetI(demuxer, WEBP_FF_CANVAS_HEIGHT);
     BOOL hasAlpha = flags & ALPHA_FLAG;
     CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Host;
     bitmapInfo |= hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst;
-    
-    CGSize canvasFullSize = CGSizeMake(canvasWidth, canvasHeight);
-    CGSize canvasSize = SDCalculateThumbnailSize(canvasFullSize, preserveAspectRatio, thumbnailSize);
-    CGContextRef canvas = CGBitmapContextCreate(NULL, canvasSize.width, canvasSize.height, 8, 0, [SDImageCoderHelper colorSpaceGetDeviceRGB], bitmapInfo);
+    CGContextRef canvas = CGBitmapContextCreate(NULL, canvasWidth, canvasHeight, 8, 0, [SDImageCoderHelper colorSpaceGetDeviceRGB], bitmapInfo);
     if (!canvas) {
         WebPDemuxDelete(demuxer);
         CGColorSpaceRelease(colorSpace);
@@ -229,7 +228,7 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     
     do {
         @autoreleasepool {
-            CGImageRef imageRef = [self sd_drawnWebpImageWithCanvas:canvas iterator:iter colorSpace:colorSpace preserveAspectRatio:preserveAspectRatio thumbnailSize:thumbnailSize canvasFullSize:canvasFullSize];
+            CGImageRef imageRef = [self sd_drawnWebpImageWithCanvas:canvas iterator:iter colorSpace:colorSpace];
             if (!imageRef) {
                 continue;
             }
@@ -377,22 +376,16 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     return image;
 }
 
-- (void)sd_blendWebpImageWithCanvas:(CGContextRef)canvas iterator:(WebPIterator)iter colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef preserveAspectRatio:(BOOL)preserveAspectRatio thumbnailSize:(CGSize)thumbnailSize canvasFullSize:(CGSize)canvasFullSize {
-    size_t canvasWidth = CGBitmapContextGetWidth(canvas);
+- (void)sd_blendWebpImageWithCanvas:(CGContextRef)canvas iterator:(WebPIterator)iter colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef {
     size_t canvasHeight = CGBitmapContextGetHeight(canvas);
-    CGFloat xScale = canvasWidth / canvasFullSize.width;
-    CGFloat yScale = canvasHeight / canvasFullSize.height;
-    
-    CGFloat tmpX = iter.x_offset * xScale;
-    CGFloat tmpY = (canvasFullSize.height - iter.height - iter.y_offset) * yScale;
-    CGFloat tmpWidth = iter.width * xScale;
-    CGFloat tmpHeight = iter.height * yScale;
-    CGRect imageRect = CGRectMake(tmpX, tmpY, tmpWidth, tmpHeight);
+    CGFloat tmpX = iter.x_offset;
+    CGFloat tmpY = canvasHeight - iter.height - iter.y_offset;
+    CGRect imageRect = CGRectMake(tmpX, tmpY, iter.width, iter.height);
     
     if (iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
         CGContextClearRect(canvas, imageRect);
     } else {
-        CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpaceRef preserveAspectRatio:preserveAspectRatio thumbnailSize:thumbnailSize];
+        CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpaceRef scaledSize:CGSizeZero];
         if (!imageRef) {
             return;
         }
@@ -406,22 +399,17 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     }
 }
 
-- (nullable CGImageRef)sd_drawnWebpImageWithCanvas:(CGContextRef)canvas iterator:(WebPIterator)iter colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef preserveAspectRatio:(BOOL)preserveAspectRatio thumbnailSize:(CGSize)thumbnailSize canvasFullSize:(CGSize)canvasFullSize CF_RETURNS_RETAINED {
-    CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpaceRef preserveAspectRatio:preserveAspectRatio thumbnailSize:thumbnailSize];
+- (nullable CGImageRef)sd_drawnWebpImageWithCanvas:(CGContextRef)canvas iterator:(WebPIterator)iter colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef CF_RETURNS_RETAINED {
+    CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:colorSpaceRef scaledSize:CGSizeZero];
     if (!imageRef) {
         return nil;
     }
     
-    size_t canvasWidth = CGBitmapContextGetWidth(canvas);
     size_t canvasHeight = CGBitmapContextGetHeight(canvas);
-    CGFloat xScale = canvasWidth / canvasFullSize.width;
-    CGFloat yScale = canvasHeight / canvasFullSize.height;
+    CGFloat tmpX = iter.x_offset;
+    CGFloat tmpY = canvasHeight - iter.height - iter.y_offset;
+    CGRect imageRect = CGRectMake(tmpX, tmpY, iter.width, iter.height);
     
-    CGFloat tmpX = iter.x_offset * xScale;
-    CGFloat tmpY = (canvasFullSize.height - iter.height - iter.y_offset) * yScale;
-    CGFloat tmpWidth = iter.width * xScale;
-    CGFloat tmpHeight = iter.height * yScale;
-    CGRect imageRect = CGRectMake(tmpX, tmpY, tmpWidth, tmpHeight);
     BOOL shouldBlend = iter.blend_method == WEBP_MUX_BLEND;
     
     // If not blend, cover the target image rect. (firstly clear then draw)
@@ -432,7 +420,7 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     CGImageRef newImageRef = CGBitmapContextCreateImage(canvas);
     
     CGImageRelease(imageRef);
-    
+
     if (iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND) {
         CGContextClearRect(canvas, imageRect);
     }
@@ -440,7 +428,7 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     return newImageRef;
 }
 
-- (nullable CGImageRef)sd_createWebpImageWithData:(WebPData)webpData colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef preserveAspectRatio:(BOOL)preserveAspectRatio thumbnailSize:(CGSize)thumbnailSize CF_RETURNS_RETAINED {
+- (nullable CGImageRef)sd_createWebpImageWithData:(WebPData)webpData colorSpace:(nonnull CGColorSpaceRef)colorSpaceRef scaledSize:(CGSize)scaledSize CF_RETURNS_RETAINED {
     WebPDecoderConfig config;
     if (!WebPInitDecoderConfig(&config)) {
         return nil;
@@ -458,14 +446,11 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
     config.options.use_threads = 1;
     config.output.colorspace = MODE_bgrA;
     
-    int width = config.input.width;
-    int height = config.input.height;
-    CGSize resultSize = SDCalculateThumbnailSize(CGSizeMake(width, height), preserveAspectRatio, thumbnailSize);
-    if (resultSize.width != width || resultSize.height != height) {
-        // Use scaling
+    // Use scaling for thumbnail
+    if (scaledSize.width != 0 && scaledSize.height != 0) {
         config.options.use_scaling = 1;
-        config.options.scaled_width = resultSize.width;
-        config.options.scaled_height = resultSize.height;
+        config.options.scaled_width = scaledSize.width;
+        config.options.scaled_height = scaledSize.height;
     }
     
     // Decode the WebP image data into a RGBA value array
@@ -473,19 +458,16 @@ static CGSize SDCalculateThumbnailSize(CGSize fullSize, BOOL preserveAspectRatio
         return nil;
     }
     
-    if (config.options.use_scaling) {
-        width = config.options.scaled_width;
-        height = config.options.scaled_height;
-    }
-    
     // Construct a UIImage from the decoded RGBA value array
     CGDataProviderRef provider =
     CGDataProviderCreateWithData(NULL, config.output.u.RGBA.rgba, config.output.u.RGBA.size, FreeImageData);
     size_t bitsPerComponent = 8;
     size_t bitsPerPixel = 32;
     size_t bytesPerRow = config.output.u.RGBA.stride;
+    size_t width = config.output.width;
+    size_t height = config.output.height;
     CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
-    CGImageRef imageRef = CGImageCreate(resultSize.width, resultSize.height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
+    CGImageRef imageRef = CGImageCreate(width, height, bitsPerComponent, bitsPerPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, NULL, NO, renderingIntent);
     
     CGDataProviderRelease(provider);
     
@@ -917,7 +899,8 @@ static void FreeImageData(void *info, const void *data, size_t size) {
         WebPDemuxReleaseIterator(&iter);
         return nil;
     }
-    CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:_colorSpace preserveAspectRatio:_preserveAspectRatio thumbnailSize:_thumbnailSize];
+    CGSize scaledSize = SDCalculateThumbnailSize(CGSizeMake(_canvasWidth, _canvasHeight), _preserveAspectRatio, _thumbnailSize);
+    CGImageRef imageRef = [self sd_createWebpImageWithData:iter.fragment colorSpace:_colorSpace scaledSize:scaledSize];
     if (!imageRef) {
         return nil;
     }
@@ -935,12 +918,10 @@ static void FreeImageData(void *info, const void *data, size_t size) {
     if (!_colorSpace) {
         _colorSpace = [self sd_createColorSpaceWithDemuxer:_demux];
     }
-    CGSize canvasFullSize = CGSizeMake(_canvasWidth, _canvasHeight);
     if (!_canvas) {
         CGBitmapInfo bitmapInfo = kCGBitmapByteOrder32Host;
         bitmapInfo |= _hasAlpha ? kCGImageAlphaPremultipliedFirst : kCGImageAlphaNoneSkipFirst;
-        CGSize canvasSize = SDCalculateThumbnailSize(canvasFullSize, _preserveAspectRatio, _thumbnailSize);
-        CGContextRef canvas = CGBitmapContextCreate(NULL, canvasSize.width, canvasSize.height, 8, 0, [SDImageCoderHelper colorSpaceGetDeviceRGB], bitmapInfo);
+        CGContextRef canvas = CGBitmapContextCreate(NULL, _canvasWidth, _canvasHeight, 8, 0, [SDImageCoderHelper colorSpaceGetDeviceRGB], bitmapInfo);
         if (!canvas) {
             return nil;
         }
@@ -981,7 +962,7 @@ static void FreeImageData(void *info, const void *data, size_t size) {
         if (endIndex > startIndex) {
             do {
                 @autoreleasepool {
-                    [self sd_blendWebpImageWithCanvas:_canvas iterator:iter colorSpace:_colorSpace preserveAspectRatio:_preserveAspectRatio thumbnailSize:_thumbnailSize canvasFullSize:canvasFullSize];
+                    [self sd_blendWebpImageWithCanvas:_canvas iterator:iter colorSpace:_colorSpace];
                 }
             } while ((size_t)iter.frame_num < endIndex && WebPDemuxNextFrame(&iter));
         }
@@ -994,7 +975,7 @@ static void FreeImageData(void *info, const void *data, size_t size) {
     _currentBlendIndex = index;
     
     // Now the canvas is ready, which respects of dispose method behavior. Just do normal decoding and produce image.
-    CGImageRef imageRef = [self sd_drawnWebpImageWithCanvas:_canvas iterator:iter colorSpace:_colorSpace preserveAspectRatio:_preserveAspectRatio thumbnailSize:_thumbnailSize canvasFullSize:canvasFullSize];
+    CGImageRef imageRef = [self sd_drawnWebpImageWithCanvas:_canvas iterator:iter colorSpace:_colorSpace];
     if (!imageRef) {
         return nil;
     }